Do everything, just a general balance. Do everything quick muscle work outs not lifting heavy weights there's no point your not entering the strong man competition.
2 minute sprints then 30 second rests is good for fitness and just keep repeating it.
What style of paintball requires the most and least fitness, I am not fit, but I want to work on it, as a starting point I would assume wood ball is a lot less taxing than speed-ball ?
I know this is an old thread but my two penneth... Burpees and any other bodyweight exercise. Light(ish) hand weights combined with aerobic exercise are the best for combining strength and mobility.
Dare I say it but you could try a home exercise video if you don't want to bother going to the gym... There's plenty on YouTube etc. Get that Lycra on the go!