Bro, generally first cycles yeild the greatest gains in size, you will do ok with just deca, but i am afraid that at the end you are gonna kick yourself wondering what could have been instead of what is. Try to come up with some test cyp dude, atleast 400-500 mg/wk, growth will be outstanding with proper diet and training. you will also compensate for chance of deca dick, which at your age could really suck. I know, I had it for nearly 2 months while my hormones returned to normal, just hit me that way. Do it up good or you'll wish you had, amazing shit, take advantage of it if you can. Good luck
Cuda