You should play whatever class you like, to be honest. Being useful in a party is great, but how much fun will you really have if you’re relegated to a role you don’t care that much for?
As with most games, I think Clerics in general are well liked. Unlike most games though, you don’t need to go all out “Full Support” for it to work. ToS is surprisingly hybrid friendly.
That said, there’s plenty of other non-Cleric roles that are quite appreciated. Linkers and Chronomancers make people very happy. If you play Swordsman, having a rank in Peltasta for bare-minimum tanking will be very welcome.
Even with no support role at all, damage classes can be great. One of the best dungeon runs I ever had was 4 Archers 1 Wizard, 3 of the archers all being pure DPS Fletchers. Our damage was so out of control we blew up the entire thing in record time.
The one exception I’ve heard about is pure damage swordsmen. Apparently, most of them aren’t very good.
So have fun and build a character you like. Note that while you can buy a Skill Reset potion for FP to reallocate all your skills, you cannot reset your choice of classes, so while you can make whatever combination of classes you want, try to pick choices that makes some sense.