How To Make A Song Without A Studio?

so im 15, i wanna rap but i have no studio.....all i have is a crappy walmart mic and audacity....i made this pretty good beat but my voice is monotuned out and it sounds lame with the beat....its hard to make a sound because the beats i can use are those non up beat ones and even then it still might sound bad....i know because a lot of other kids my age on youtube recordings sound proffesional......