What I found helpful was watching videos by Antonio Centano https://www.youtube.com/user/RealMenRealStyle

I'm going to presume you are male... not trying to be sexist, it's just a guess. If you are female I don't think this advice will be helpful (women seem to have it a lot harder when it comes to these choices, esp. with what is suggested by Antonio, which is largely ignoring current fashion).

He teaches the difference between classic style and fashion, and focuses on the former. While many of his community are probably interested in dressing way more formally than you are (and frankly seem to long for time when it was more socially acceptable for men to wear suits everywhere), he teaches principles, which can be applied to many different styles of dress.

The older videos are more fundamental and tend to be better IMO.