To make it as simple as possible, all you need to bulk up is tear down your muscles (by working out) and consume more calories than you burn.
As for the stamina part..do exercises that will mimic what you'll be doing in football, such as sprints and agility exercises.
Interval training is the best way to go if you're training for football.
Then, just keep lifting however you currently are, but eat more! (healthy foods of course, not junk)
