Aside from when you reach the level cap (and when there XP events that give more TP per mob kill than XP) you cannot farm specifically TP. You get 10% XP as TP - grinding lots of mobs isn't going to change your XP/TP ratio. You want to quest, quest, quest. If you really want to go fast, you want to get to Johnny Dutin in Varanas and get to Coast of Opportunity, even if you don't choose a third class (though if you do, up until level 40 Mage is soooo much better than Scout, though you may want to go the archetypal P/S/K for damage/healing). The XP there is a lot higher than in the old zones.
Essentially you are about to hit a TP starved time. From about 25-45 levels you don't have a lot TP. You are constantly learning new skills that require TP, and the XP between levels isn't high. Get to level 50 or so, and the XP required for each level means that you have lots of TP, that you can invest where you will. Raising a skill from 55 to 56 takes about the same TP as to get from 1 to 45. Or something like that.
Best thing is to keep most of your skills not maxed. As a low level Priest you should really think of yourself as a Water based Mage. You need to level, and that means killing stuff as quickly as possible. Intel over wisdom, damage over healing. Imho at least.
Don't max stuff, at least leave it one or two levels behind your level if you are starved for TP. Even five levels won't make a lot of difference.
Let me know if I have failed to convey any points or if you want clarification of anything.
