Select avatar when entering the space
When entering the space, you can select avatar and integrate Ready Player Me to let users select avatars
Can you elaborate what exactly you'd like that is not currently implemented? The engine supports Ready Player Me integration and avatar upload already.
When users enter the space for the first time, let them choose avatars and build avatars themselves.

I think it will be very cool. People like it better and increase the freedom of avatar
Yes, a character creator is being planned for. There is a UI for changing avatars, and you can upload your own already.