Personal Renovation

So....I'm a new girl! I found the app on itunes first and joined about a week ago and I am absolutely in love! This site is amazing! Now that I've become acquainted with the site I'm ready to make some friends, get some motivation, and share encouragement and tips with everyone else.
A little background info, I am 24 years old and I just recently quit dental school because I was completely and utterly miserable and now plan on pursuing a career in medicine. This whole transition has been quite stressful for me and I have packed on 10 pounds in a matter of 2 months and realized that I can't keep doing this to myself, I have to get healthy and I could stand to lose more than 10 pounds.
I currently work for a cardiologist which is motivation itself when I have to fill out charts with a medication list the length of my resume! I have recently became obsessed with the treadclimber, I try to work out 4 times a week but it usually ends up only being Mon-Thur. I would like to find some upper body strength exercises because I would love to tone up my shoulders and arms so if anyone has any suggestions let me know!