Warlock Spec while Leveling

I’m new to Warlock and I’m up to level 36 but unsure of talents. I’ve done some reading and some say drain tank with Succubus. Or put talents into Demo to get Felguard.Not sure if I should reset mine? I’ve put some into Affliction and Demo so far.Affliction: 5 into Improved Corruption, 2 into Drain Soul and 2 into Soul Siphon.Demo: 3 into Imp, 3 into Demonic Embrace, 2 Fel Synergy, 3 into Fel Vitality, 3 into Sayaad, Soul Link, Fel Domination and 1 into Unholy Power.Succubus doesn’t hold hate very well unless I’m playing wrong which I probably am. But damage seems alright. I run out of mana fast if I use dots, Immolate, Drain Life and Shadow Bolt. Life Tap helps some but can’t keep up.Should I reset and max out Shadow Bolt, Bane and Demonic Power? And use Imp for dungeons and Void Walker for soloing? Not sure if I should keep going for Felguard or not.Thanks for any advice, Warlock is fun but I’m terrible so far.