My main quest tells me to go to Winterhold college. To get into the college she demands me to do a spell. I buy said spell(conjure flame atronach), but I cant do the spell. even if the magic bar is full it just does a clicking noise

I am level 8, my magica is at 110.

Do i have to do side quests now, and if so where do I find them?

Hey if you have a shout you should be able to get in through some extra dialogue.

She doesn't accept my shout, and are you sure about the extra dialog, cuz I cant find it, she just demands her spell time and time again

Where do you go to do sidequests?

IIRC, doesn't she ask you to cast a fear spell?

she wants a flame attronach, thats what the quests say

your magicka just isn't high enough. Conjure flame atronach costs 150 magicka so either put some points into magicka after leveling up a few times, or get some enchanted gear that will reduce conjuration cost

Back out and start over, she will not except the shout unless you first say you are the dragonborn.

The base cost for flame Atronach is 150, I don't know if you summoned it before, but I'd try summon familar or if you picked up the book in helgen sparks.

For sparks you will have to back out and then say distruction instead of conjuration.

Or just go down to the town ( slightly outside it) preferably and practice til you can get it to summon