Now I'm playing both sides of dawngaurd and just finished the vamp side but im wondering how long it takes to get all the perks for the skill trees as I want all the achievements for skyrim (again) but it seems it's gonna take awhile. Is that how it is or am I doing something wrong?

Depends on how often you feed, If you find a place with ALOOT of weak enemies i figure you can level both quite fast.

How exactly do you feed? Like the right process if there is one or can I just walk up and feed?

To get Vampire perks you have to be in Vamp Lord form. To get perks, either kill enemies with the Drain-douken, or kill them with a melee power attack. That should result in a bite, and a perk gained.

So it does take forever

I have tried both also and the werewolf seems to go faster. And to be safe i would use the vampire drain to get the level up progress for the vampire lord as the power attack does not register sometimes. Also, avoid having a follower with you as they steal the kill sometimes, and in Serana's case, most of the time.

Yes I have noticed that but I play on master difficulty and I like her quite a bit