Say I want to talk about myself cooking in my video, should I use "this is my first time cooking" or "this was my first time cooking"? I heard someone say something about using present tense when you are telling a story or describing something.
If you are speaking the words as you are cooking, you should definitely use the present tense. When speaking about something that happened in the past, you may use the past tense or the historical present tense. The historical present is not typically used throughout the entirety of the story, but rather used for effect. It is typically used for exposition or to describe background information. For example:
So I'm on the bus and this woman is just staring at me. Suddenly, the bus screeched to a halt and she tumbled right into me.
The historical present should not be used in formal contexts, but it can be useful in storytelling. It's a matter of personal taste and judgment. If you don't feel comfortable using it, you can put everything in the past tense.