First of all, do not level 'e' first. Ever.

"q" is your main sustain, harass, zoneing ability, and everything untill you have the items and levels to instakill waves. (Level reduces its cd and makes it even more spammable, even 30 hp every 9 seconds is decent as that's basically 3 per 1 or 15 per 5.)

Your first buy should be boots + 3 hp pots or possibly a Null (400g MR item) + 2 pots. (Though you see a lot less spirit visages nowadays and you really shouldn't get merc treads on vlad)
Rush revolver > Rylai and proceed to build based on enemy... (Revolver 12% spellvamp really amps up your sustain and adds sustain to your 'e' and 'r')

Don't worry about killing the enemy pre 6 as it won't generally happen unless they mess up.

Vlad is not a all in champion. He is a go in after the initiator, r q e q (auto q and e whenever able) till they focus you low then pool and get outta there. Continue to q e from as safe a distance as possible until the fight is over or your entire team is dead.

Try watching a video of somebody, like dyrus, playing him who knows what to do. It helps more than just reading a guide.