Few questions for new guy

Is it possible for new players to even play these events? I maxed everyone regular boards and got to 7* , put equip on them and maxed everyone’s levels. But these bosses levels get so high seems impossible without zenkai. I’m stuck on level 60 on ssb goku event & around 50 on vegeta’s. Also how in the world do you complete 15 missions when there is not even 15 missions?

Another example is hyperbolic mode and co op modes I just unlocked.. one combo and you’re dead even with strongest characters. Maybe I suck but it’s so hard to break out of combos once you get caught. I always try to vanish try to attack and then they recover so fast vanish and combo me to death.

Same thing with ultra goku i completed every mission that doesn’t require him. The 3 left all require him to play but I’m 20 short of gaining him. How in the world can I even finish when last missions require him? Maybe I should finish story mode first but I didn’t want to let all these events pass me by in the mean time.