Welcome to Mastodon new folks!
If you're very new to this social network, please consult #mastotips and #feditips: there's plenty of good advices there because we tend to care about each other around here.
Please also consider using the CW function directly (yes, we have one <3) if needed (could be for shitposting, sensitive topics or to post very personal stuff or calls to action) and use image descriptions. You can also post to your followers only or publicly, etc.