I'VE CHOSEN TO START EXCERSING! BUT I HAVE SOME QUESIONS!?

Lol you are skinny enough trust me. Everyone has that when they bend over. Its just skin. But there is nothing wrong with getting healthier. I suggest you burn fat and tone. You don't have a lot of fat to burn but it is still good to incorporate running. You will see a difference in maybe a month. Thats how long it took me to see a difference when i started weight lifting.