Mostly just check the sidebar of any particular community before you post. There are upvotes/downvotes but no persistent karma. There are some communities and instances that are heavily moderated, try not to be offended if you catch a ban without ever participating its probably not personal. Also you can block users, communities, or entire instances, so you’ll have pretty good control of what you want your feed to look like if you familiarize yourself with those.

Nice to meet you, and hope you enjoy your time here