If you go to your skill panel, you will notice 2 rows of open "skill slots"
If you click on any of them, you will notice underneath, there are a skill tree that appears (a menu style listing of all the skills available to you at your current stage in the game), you can click through them, and invest points in the ones you want.. (you will see right at the bottom of this panel how many skill points are available to the character). Just buying them only gives you the ability to put points in them... only after putting points in them can you use them...
(Alchemy extract doesnt show up in your secondary action, when you right click on an "alchemy plant" you will have the options available to make potions.)
