As a warning, Balmung is still currently on lockdown and won't accept new or transferred characters. 
The alternative is currently Mateus (or Omega and... Louisoix, I think?... if you're EU), though there are small RP communities scattered about a few other servers like Jenova and... I wanna say Faerie. In either case, even though Balmung's off the market right now, there's still plenty of other places to get your RP on! I wish you the best of luck and hope you find yourself your own little place in the RP community.
(And, of course, there's always the options of RPing via Discord or on the forums here which can happen regardless of server!)
The alternative is currently Mateus (or Omega and... Louisoix, I think?... if you're EU), though there are small RP communities scattered about a few other servers like Jenova and... I wanna say Faerie. In either case, even though Balmung's off the market right now, there's still plenty of other places to get your RP on! I wish you the best of luck and hope you find yourself your own little place in the RP community.
(And, of course, there's always the options of RPing via Discord or on the forums here which can happen regardless of server!)
~