Before you start working with Alchemy, you want to get the trophy.  To do this you need to start the Quest which is listed below.  You need this trophy because it gives you a skill modification.  Everytime the trophy goes up a level your skill mod goes up too and the skill mod makes your skill level seem higher.  Since you haven't started this skill yet you can do the Beginner Alchemy Test.  PoR Alchemy Trophy

The potions I am starting you out with are Elixir of the Avian and the reason is because it will increase your wisdom so you can create 1 potion then put it in your potion belt and drink 1 to raise your wisdom which you will need when creating potions.  When your trivial goes high enough that you can make the next  line just click off the spell effect after you've made the next line and drink one from the new line.  Sell all the potions you make to a merchant so you can get money back.

The Serpents Spine expansion brought this quest TSS Training Quest which will help you get your skill to 50 at no cost.

Everything after that requires mob drops which means farming and the items you will need to farm are most likely for high level mobs.  So, you might as well create a Ranger and start foraging Nodding Blue Lily's in the Dreadlands so you can create: