grogerson: Just follow the quests you're given at first, then just roam the countryside, tunnels and dungeons. If it attacks, kill it. Just don't get a Wisp angry with you... Most encounters respawn rather quickly, so plenty of XP is possible but so is the chance of getting seriously hurt or killed. Leveling up is automatic. The accruing training points are another matter.
As for using those training points, you have to find a trainer who will raise your abilities (strength, dexterity, intelligence) and skills (hit points, combat, mana). Increasing strength increased your hit points, dexterity improves combat, intelligence boosts mana. Most trainers will increase one ability or skill, a few two or even three (with bonuses to the appropriate skill), but be ready to pay for their services.
what exactly is my max level? do i need to be careful where i put those trainer points? what do i do if a companion gets killed/ whats the cheapest way to ressurect him?