You should be fine. The boss battle isn't too difficult and you have 3 other npcs helping you.
What?DUDE! YA GOTTA YELL SPOILER! HE AINT PLAYED IT YET!
So right now, I'm level 26. My armor is a mixture of daedric, ebony, steel plate, and orcish. My weapon is an Ebony War Axe. Do you think this is enough for killing alduin and that dragon priest? I've improved a lot, but is this enough?
I've already watched people play it on youtube, I practically memorized the place. The question is: do you feel too overpowering when you finish? Does it take all the fun away after?
But you would have to kill Paarthurnax... Who is a total broAfter you kill Alduin, go speak with Delphine and hunt the rest of the dragons down.