So i am new to using homebrew on here. 

one if my players wants necromancer and i found this

https://www.dndbeyond.com/subclasses/101552-circle-of-death-necromancer

I enabled content sharing and have the homebrew content checked but he or i cant access it when creating a character. 

Or is this a build a druid around these skills type deal?

You need a Hero tier subscription to be able to add homebrew made by others into your collection and be able to use it.

i have the highest tier

Is the character at least a level 2 Druid? This is a subclass from the Druid class.

okay Thank you. guess i wasnt understanding it right

SO When making it level 2 Do i have to have a side note or page saying the spells he has or is there a way to have them show on the character sheet?

When viewing the character sheet, there should be a spells page where you can track prepared spells.

 Personally, I recommend not allowing this homebrew and instead require that it be finished, functional, and balanced.

But to use homebrew, make sure you add it to your collection and turn on content sharing.