Senior Show Off

So I have no knowledge of the piano and guitar, except like a years worth of piano lessons, and August Rush (which iIam sure doesn't count..) Me, being the odd person I am, thinking, "Oh if I start now I could totally have a song down on either in a year!" and the thought of maybe all these profesh songs that I want to play to sing along to for senior show off...are for professionals. Professionals as in, have been playing there whole life and have ever technique down, and I wanna learn "Bang Bang Bang" by Christina Perri (which has a slightly intense piano solo in the midst of the song) and then I thought oh I could learn "Speechless" by Lady Gaga. I think the best thing to do is to probably hire my cousin Shalei to just play for me?  Then, the only sense of accomplishment I would have is singing in front of the whole school. This has got me stressed and it isn't till the last week of school..Next year. wouldn't "Speechless" sound awesome with piano, and violin??