1. Find a song you like on http://freemusicarchive.org/ (https://creativecommons.org/about/program-areas/arts-culture/arts-culture-resources/legalmusicforvideos/ ) (music here is licensed under Creative Commons, so you aren't pirating anything)
2. Press the download button (it's the down-arrow next to the song) and save it to your files
3. Open Audacity
4. Under "File," press "Open" and find your song
5. You should see your song pop up in the middle like this ---->
6. Open the "Effect" menu and try 3 of them (The change tempo, change pitch, and change speed effects are particularly useful)
(This is another good tutorial, but I don't know if the video will work for you: http://www.freeaudacitytutorials.com/tutorials-for-audacity-beginner-1-screen-and-basic-setup/)
2. Here are some ideas of things that you can do in Audacity, but you can't watch the videos at school: https://audacity.wonderhowto.com/how-to/
3. If you haven't looked up remixes before, try doing so outside of school. A good place to start is here, because this song has been mixed with EVERYTHING: https://www.youtube.com/playlist?list=PLFeWlsJofrltFtRu46b6_ytwRKYobpK0D