Don't use a subdomain for your server name; you can delegate a subdomain via well-known endpoint for the real server if needed in the future but this lets users keep a clean domain.com for their contact.

Synapse / Element are the go-to, maybe unfortunately; most other things lack features or use outdated deps. I run a Cinny webapp locked to my HS so people can easily try it out, which is a nice-to-have; but most end up installing Element when they adopt Matrix. (Personally I run fluffychat for mobile and Tuwunel server (forked tuwunel<-conduwuit<-conduit) but they can be a pita. Just stick to the defacto standard stuff)

Docker or Nix trivializes setup configuration. Similarly, Caddy is a cheat code for managing SSL, reverse proxy, and endpoint hosting.

If you use synapse, there's a handy admin webui thing people use which is highly encouraged by the sounds of it.

The biggest friction point is usually setting up TURN/STUN for VoIP etc. Massive pita but a using a VPS may help you a lot there if that's something you need (being behind NAT makes it very difficult and risky).

Make sure you use registration tokens so your server is private (this is usually the default I think)

Do you have any more specific questions or concerns?