New to WE, need help with List Direction

Hello everyone!

I recently came into ownership of quite a bit of world eaters/CSM boxes, including the release box, so figured I should try to learn to play the army but I am not 100% sure what I own is worth keeping and what I should leave in the box for another date.

So far I own:

-2 Slaughterbounds

-10 Khorne Berzerkers

-12 Eightbound/Exalted Eightbound (all unbuilt so can be either if I am correct)

-20 Jakhals

-1 forgefiend/Maulerfiend (unbuilt)

-1 Heldrake

-1 Master of Executions

I assume using the Possessed Slaughterband detachment is my best bet, but was hoping to get some advice and/or direction from those that know more than me in this regard.

I am not a tournament player by any means, but want to make sure I won't lose my games at listbuilding.

Thank you in advance!