Well, my friend. There isn't a certain pattern of learning all the new word pronunciations. However, what I can really suggest is the conventional way of learning new words.
Once you confront a new word,
1- First, you should read or listen to the pronunciation of the word in your lexicon. Personally, I even try to seek alternative pronunciations in several countries or pronunciations in dialect.
2- Then, it's time to read the definition and examples.
3- You should make your own examples.
4- You should try to reuse the word after a few days so as to elevate it into the range of your active words rather than passive ones.
As you see, looking up the pronunciation is the first and initial step of looking up the meaning of a new word. However, I believe once someone has got engaged with English for certain years (10 years+), they can guess the correct pronunciation of new words most of the time, especially when in comes to intonation and stress. (It's not only a matter of syllables).