ActualCrackhead if a server requires a level to play it's either misconfigured or a bad server in my opinion.
But if you really wanna play on it either unlock all or set your level to 80 depending on what you wanna do.
setPlayerData experience 999999999 for level 80 or if you want level, prestige and unlocks https://plutonium.pw/docs/unlockall-max-rank/
iirc in the barracks menu we have a "customize your stats" menu where you can do that as well