Welcome brother, I was also banned from Reddit after being active on it since the great Digg exodus. For reference the post that got me banned was when I pointed out that American ADA laws guaranteeing public access have been around much longer than EU laws which is why they likely did not see as many disabled people in public places in Europe as they just can’t physically access them until the architecture catches up. Apparently that was considered bigotry in a European sub and was the final straw that got me permanently banned.
Lemmie is by and large much more liberal and left leaning than Reddit is. (at least the subs I’ve visited have been.) I haven’t seen the retaliation or pre-emptive bans for just joining or posting in a particular sub that I saw over the last few years on Reddit though. I also haven’t seen any bans due to frequency or activity.
Much like Reddit if you make a comment that goes against a subs meta or against the beliefs of the moderators they will find some way to ban you from their sub. I’d say many subs in Lemmie are less encouraging of discourse that does not fit within their beliefs.
So even if you probably can’t get a site wide Lemmie ban you can still be banned from individual subs.
Post and comment away, just keep in mind if your content does not fit the subs meta they will probably find a way to ban you from the sub.