1. I'm pretty sure you'll just have to find that yourself. Just find out what song they used, search it up, and find a download. There isn't much to help you with that, I just end up trying to find a download either on YouTube or Google.
2. There are lots of places where you can make soundtracks. The ones I have used are Fl Studio 10 and Logic Express 8. Logic is only for mac I think so try Fl Studio 10. It's not free but the trial can do everything. The only thing it can't is save a project. So you will have to export the soundtrack you made before you close it. Here is a link to a download of FL Studio:
http://fl-studio.en.softonic.com/