So im goin to rebuild my back wheel and just need to know if theres anything i need besides a new hub and cog?

thank you for any input

Lockring and possibly a crank/bottom bracket in the event that your current setup doesn't give you an appropriate chainline. Other than that enjoy.

yeah, you also need a knowledge of wheelbuilding, new spokes, and new spoke nipples. that or a hub of the EXACT same dimensions as the one you are taking out, which if you are going from a road hub to a fixed hub, is very probably not going to be the case. don't forget to get the same spoke count.