Some key points to a necromancer (especially at the early levels):
* Make sure to summon the right level pet. If you are level 10, Bone Walk can summon a level 7-9 pet. To see if you have the right one, check how much damage it is doing. If you find you have the level 7 or 8, just use Reclaim Energy until you get the highest level.
https://wiki.project1999.com/Bone_Walk
* Use Mend Bones to keep your pet up. You should be able to kill yellow mobs if you have your level 9 pet out. Toss it some weapons too.
* Just let your pet take 50% exp until you hit level 12 and get new spells. You can really do this the whole time until you feel comfortable with your spells.
Doing this should get you to level 16 without a problem. Hopefully by then you will start to see how the necro spells work and how to use your pet more of a DoT and get all the EXP to yourself.