I need 2 more levels for the Heroes Quest =[ Anyway to lvl up quick?

collect/ buy the materials for the highest level pot you can make and make them till you get 45. Simple and straight forward.

Buying herbs at such low levels is not worth it. You should kill chaos druids for the herbs, and make pots with those. Later, you could sell the herbs you've got left if you don't plan to train herblore after doing Hero's.

You can make quick 2 levels on Serum 207 potions (if you have done Mort'ton Shades quest). Buy tarromin cheaply from players (200-400ea), burn some trees for ash which is a second ingredient and here you go.