Hard to describe since fashion is an art and it's something you have to develop, hone, and refine through experience creating and consuming art

Start by just following as many sources for fashion as you can to get an idea of what's trendy nowadays and good outfits for inspiration. Copy ideas at first and then when you get a hang of how to match colors and silhouettes, you can start doing your own thing. Also check out everybody's outfits when you're outside and add nice ones you see to your memory bank

Instagram and tiktok in my experience are the best online sources

Also, fashion in the East is taking over the entire world and becoming more influential than ever. Especially now since baggy/loose is in again and Eastern styles have more of that. Look at what the Chinese, Japanese, and Koreans are wearing as well