You need to choose the communities that suit what you want to write about so I can't suggest which are the best. I hope you'll use my own though. THE WEEKEND.

Communities are a place to drop posts that follow the community-brief, meaning they are topic-specific, or theme specific. Curators are those who read posts and vote upon them.

Communities will have their theme and rules listed so make sure you read and follow it or the community admin and mods will probably mute your post. In THE WEEKEND I have a posting guide pinned to the top which would probably be good for you to read.

I hope this helps.

Also...I wonder why you call yourself a beginner and say you're new when your account was opened in 2018?