First of all, having worked with a fair number of Indians, Pakistanis and Bangladeshis over the last few decades, I can say that you have a very mild accent overall. This leads me to assume that your interlocutors are either linguistically naive (have not spoken with very many non-native speakers), or willfully stubborn (not willing to make any extra effort to infer what you are saying). Leaving that aside, I can give you one big hint about American speakers: we talk with our mouths open more than many other language speakers. A less charitable explanation is that this relates to talking loudly and calling attention to ourselves, but let's not digress too far. Let's start out with a simple example.
First things first, I took the liberty of transcribing your recording for easy reference. I include it here:
First of all, thank you if you're listening to it.
- I'm Simran and the reason I'm recording this audio is, umm...maybe silly, but anyway.
- So, I moved to Canada about nine months back; and so, I'm pretty new here.
- And, basically I've been feeling like I have to sort of repeat myself a couple of times when I'm speaking to our native Canadians or Europeans or people from States, because I have bit of an Indian accent and that sort of does not help with smooth communication.
- I mean, it's no fun when you have to repeat yourself over and over, so, umm...yeah.
- I would just love to know what could I possibly change to sound more native or more understandable to natives.
- Umm, yeah, that's pretty much it; and I really look forward to your responses.
- Thank you.
Believe it or not, I can identify your accent on the very first line, when you say "Hi guys". It's very subtle, but you change the diphthong "aɪ" into "ai" in "guys". To understand the sound differences between your (presumably Hindi/Punjabi) accent and the typical neutral American accent (AmEng), we do need to appeal to some linguistics. I am not a professional linguist, so take anything I say with a grain of salt. However, I feel I can explain some key differences with just a few concepts, so please bear with me.
If I try to describe the pronunciation of "guys" in very explicit terms, it would be like so: "g-ah-I-z". The phoneme /a/ is formed with an open mouth, tongue low, lips unrounded. The small capital /ɪ/ actually represents what we call the "short i" sound in English ("tin", "bin", "win"). Whereas /a/ is formed with the jaw low (to make the mouth open), /ɪ/ is formed with the same mouth shape, but with the jaw mostly closed. Now, the way you pronounced it is more like: "g-ah-ee-z". The /i/ phoneme is what we call the "long e" sound in English ("cheese", "bees", "knees"). Almost every other language pronounces /i/ like "ee", which is why IPA uses it as such. Since "y" used as a vowel generally operates like /i/, it is natural and logical to pronounce it like "ee", and even Americans do so in many circumstances (all the "-ly" suffixes: "broadly", "hastily", etc.). But American English, as you know, is not natural or logical, so we also pronounce it like /ɪ/ ("idyllic") and /aɪ/ ("fly", "tyrant", "guy").
Now, the difference between /ɪ/ and /i/ is fairly subtle. As you can see in the vowel section in the Wiktionary IPA reference, /i/ is one of the most "closed" vowels, meaning your mouth is mostly closed when pronouncing it. But /ɪ/ is just a little less closed. The other difference is that when pronouncing /i/, the sides of the mouth are pulled back further (hence, why we say "cheese" to take pictures: the phoneme forces a kind of smile). The "opposite" sound is /ɑ/ ("father", "naught"), where the mouth is wide open, and there is no opportunity to pull the sides of the mouth back, really.
This phenomenon occurs again when you say: "Thank you". I would transcribe your pronunciation as "th-eh-ee-n-k", whereas the AmEng version is closer to "th-eh-n-k".
So while I can clearly hear the /æ/ sound, it transitions into /i/ in a subtle but noticeable way. You can probably see the beginning of a trend here: your pronunciation includes more "closed" vowels compared to the AmEng version. And this is what I meant when I said "we talk with our mouths open more". I meant that literally! ;)
Not to beat a dead horse, but the only word I missed when I listened to your sample was "Canadians" on line 5. It sounded like "comedians". I was curious about why you were calling out comedians in general, until I realized you were talking aboot Canadians. ;) Again, we can call this the diphthongization of /æ/ to /æi/. It will be difficult, but if you want to sound closer to AmEng, you will need to stop transitioning most vowels into /i/, and literally leave your mouth open. When pronouncing "Canadian" in a mirror, the second syllable should feature an open mouth. My guess is that your jaw never lowers at all when saying this word.
Again, when you say: "First of all", you pronounce "all" like "oo-ll". AmEng speakers hear the same vowel as in "fool", "pool", "dual", but they expect to hear the vowel as in "mall", "doll", "call". And again, /ɑ/ is an open vowel, while /u/ is a closed vowel (I would transcribe the IPA for your pronunciation as /ul/, while AmEng is /ɑl/). Another indication that your pronunciation of "all" is non-standard AmEng is that I predict you round your lips when you say it, whereas an AmEng speaker says it with a mostly open mouth, to the point where you can probably see the tongue touch the back of the teeth when pronouncing the "l". Try saying this in a mirror and see how close I am.
Articulation of W and V Sounds
As someone mentioned in comments, a common artifact that I notice is switching 'v' and 'w' sounds. The most famous such example is surely Pavel Chekov, in Star Trek IV, when he was mocked for saying "nuclear wessel". You pronounced them in the standard way, so this does not appear to be an issue for you. However, I notice it more when a word starts with a 'w' or 'v', and more so for less commonly used words. Surely you hear words like "when" or "way" very often, but "victor" or "warping" less often. One of my Punjabi friends often pronounces "vine" when referring to "wine", most likely due to the lack of distinct "v" and "w" sounds in Punjabi, according to this source. If you are asked to repeat a phrase that includes a leading 'v' or 'w', this may be why (especially if two words are identical except for a leading 'v' or 'w'). "You ready for vine?" could mean: "I heard there's an interesting video on the Vine service" or: "Let's go to happy hour already!". It takes a bit of parsing the context to understand which is which. Sometimes he avoids the confusion by switching to Italian and calling it "vino", which has no ambiguous "w" partner, and plays off the fact that "vine" and "wine" are intimately related.
Probably the most noticeable grammatical difference between Indian and American English is the use of determiners ("a", "the", etc.). As others have noted, Indian English tends to drop these in places where AmEng considers them mandatory. On line 5, when you say: "...people from States...", most folks will know what you mean. But AmEng speakers expect to hear: "...people from [the] States...". It's probably not easy to notice when you have done this, unless you have a buddy that points it out consistently for you to help you learn.
I think that practicing in front of a mirror, and listening to pronunciations on Wikitionary will help you absorb the AmEng accent. It will be a slow process, because your brain is already programmed to speak the way you do. But the more you can see your tongue operate while speaking, the closer to AmEng you are likely getting. And if you hear less "ee" sound when listening to your voice, you are probably also making progress. Good luck!