I don't mean to brag... scratch that, actually I do. I just got 22 kills and zero deaths with Captain Spark, best game EVER
Read this:
http://mondaynightcombat.wikia.com/wiki/Captain_Spark
It gives you a very good oversight of what all of Spark's abilities does. In general you want to use your teleport to get into the 'jungle' as quick as possible (the upper level were the neutral bots are). Stick around up there for a while and farm the neutral bots for a bit, you can easily just run backwards and shoot them with your ray gun, and they give A LOT of experience, you'll usually reach level 2 after killing only a couple of them.
While you're in the jungle, you want to keep on the lookout for players on the other team that are easy to ambush (either they're low on health/already being attacked by your team or are close to the edge of the map so that you can just jump down and throw them out with your Flip Switch throw).
In general focus on leveling your teleport (remember, it can go through walls/ceilings/floors if they're thin enough, making it the perfect tool for escape/chasing down enemy players) and damage first, but make sure you're not neglecting the health power up. Get good at judging the roll distance from 'reloading' your sword, it is a very key part of your general mobility, especially because you can roll up to people and quickly throw them with the Flip Switch.
To be honest, I won't recommend you start using Spark until you've learned the layout of the maps, since getting around and behind enemy lines so that you can ambush the enemy team is a key part of his strategy. I would stick to either a support class or the enforcers and focussing on pushing the bot lanes when learning the game.
And finally: Don't die! The hardest part of this game is learning when to push your luck and go for the kill, or to just get out of the way and run back to the spawn room to heal/buying some regenitol.
Edit: Also, make sure you set up your endorsements, and if you've got the CC for it, buy the Death Dodger product (products are like perks from CoD). If you survive on low health for a bit, it will teleport you back to the spawn room.