Just a warning, skill resets cost a lot. I rather bare through and just Frost Bolt until Lv25 than spend cash/zeny on a reset.
I went through as a priest, Holy Light-ing to Lv50. So it can't be that hard, unless you just don't have patients and want to 2 shot everything.
As far as I know, most classes are slow from 1-25, then it gets fun once you advanced.
Side note: Varetyr Spear is very useful in PvP. Pair it with Frost Diver and that's 160% at Lv5... Not to mention, instant cast with 3s stun. This is your finishing move when your target has 50% HP left. Another tactic, the stun gives you a chance to run or finish off your target with Jupiter. Launching only Lightning Bolt or Jupiter Thunder at someone will only get your kills stolen.