Used to be fat,did some mountain biking now I am skinny 144 LBS ,what i want to do is get some upper body strength.I hate my skinny arms i got from mountain biking. I need to get some muscle mass on it. I know i wont get ripped without lifting but i have had enough of the girly arms.

I dont have access to a gym in the sense that i live with my mom(asian parents) she says i am only allowed to join a gym the day graduate or move out.Wants me to be fit though,infact encourages natural stuff like pushups,pullups,running,mma infact she has even spotted me during pushups and bought me a boxing bag. Whats the best i can do in this situation to get some upper bod,until i graduate in a year or so.

My wrists are so skinny that pushups hurt like a bitch.