Welcome to the game!
As a long time mastermind player I can assure you necromancy is a most excellent primary power set. Check out the mastermind subform for ideas about combining with secondaries and how to play.
Overall enjoy your first time through. One teams level up the old-fashioned way, avoid fast XP farms, you really only get one time to do the new experience. Blue side has the older content, red side has the newer content and generally the more interesting story arcs, but there's good things to find on each. Maybe run a character on each side. And of course gold side but that's a little tougher to do solo, and gold side ( The going rogue expansion) is best done when you've got a little more experience under your belt.
You won't really make money for your characters until you have level 50, and that wouldn't work too much about it.
Honestly necromancy/dark miasma is an excellent starting combo it requires very little investment to make work well, and gets even better once you start to work on your build at end game.
If you are on everlasting and I'm on feel free to ping me for help or teaming. My global is @force redux.