All of the ffx characters are multijob in their base trees except for lulu whose a straight up blm.

Rikku is a thief/chemist
Yuna while has the summons is more a white mage in gameplay if you dont use the aeons. She gets esuna, nul elements, holy, pray, cure series, autolife etc
Wakka is a weird archer/green mage with a gambler overdrive
Tidus closely fits time mage and warrior classes but with a focus on speed/evasion over defence
Auron is a samurai/paladin without the magic
Kimhari is blue mage, he can fill any role in the party once you get him moving. Its just his start position on the standard sphere grid sucks. Advanced grid he's a gamebreaker.