Hello and welcome to the fediverse.
I would recommend piefed over lemmy because they can reach and connect to mastodon. And there is better moderation tools, tag, hashtag.
There is https://tarte.nuage-libre.fr/ it is a steady rock solid server.
We are building a piefed instance with a better and shorter domain : https://forumlib.re/
The same admin team will manage it but it takes time.
That's the first part.
The second part is that we don't know your needs : communication ? Promo ? Social network ? Forum ? Microblog ? Teamwork ? Collaborative app ?
NB : We answered in english because we don't know which language you are the most fluent with.