You seem to have a reasonable starting force.
And I see 2 rough options for you, one more kabalite focussed with a squad of wyches and the other slightly more cult with a squad of warriors. Later on it will be important to get some more command points but for 500 points and just learning the game I would worry less about that.
Kabalites with some wyches:
Archon (with huskblade/ pistol)
2*5 warriors (w blaster)
2 venoms
succubus (w glaive and maybe pistol instead of a wych
#6)
6 wyches (w power sword and wych weapon)
raider
This should get you to 500 ad in some phantom grenade launcher to get to 500.
Archon (with huskblade)
5 warriors (w blaster)
raider
succubus (w glaive)
2*5 wyches (w power sword and wych weapon)
venom
3 reavers
This would leave your HQ to run, as well as being slightly low on anti tank, you do still have enough points to either get a blaster (for the reavers) or 2 blast pistols (1 for each HQ)
When expanding your army in both cases it might be good to get some more anti tank/heavy infantry with a ravager, as then battles also become larger and you are more likely to meet tanks.