Invest in a home gym; get an excersise bike or something of that nature, even dance dance revolution works. do atleast 15 minutes of cardio, and then weight lift to your max capacity for about 5 reps, stop for a moment rest again and do this for about 10 sets.
you will get bulked up...
as for supliments, remember those are expencive as well; but I would try whey protien, it takes like shit, but if you can stomache it, and take a daily vitamin, eat lots of veggies ect...

just common sence really... if you don't have any weights, like heavy weights a home gym offers, then you might as wel not even bother or just join a gym because your not going to get muscles otherwise.