Transfer into an elite school?

<p>I appreciate all comments/references and will definitely reply to any questions you have if I am capable.
I just got my results back from the college application process, and the results were fair but not all I could hope for. I didn't take the essays, recommendations, and resume writing as seriously as I should have. I was thinking about not going to college and enlisting in the military at the time. I was still considering this until recently, and my senior year grades are an 88 average instead of my usual 97.
But recently I had a change of heart. I looked at my grades and my prospects and realized I want to put in one hundred percent effort instead of just doing what I have to to get to the next step. I decided that I do want to attend college and was considering applying to transfer out of the college I was accepted to, the University of Pittsburgh, after a year or two for a more competitive environment and a more classic campus (Pitt is spread throughout the city) that I think I will grow more within.
If I was considering applying to schools like the University of Pennsylvania, Johns Hopkins, and Washington University of St. Louis, when should I transfer and what should I do in the meantime?
Thank you so much I really appreciate it</p>