I have been using my parents Apple ID for a few years now to buy music and apps but now I am going to college and I don't think they want me to continue buying music and other stuff with their money. If I switch over to my apple ID on ITunes and my IPhone, will I lose all the music that I have on my phone.
You can ask them to set up Family Sharing, and then get them to invite your new Apple ID to the Family.
On the organizer iOS device, go to Settings > iCloud > Family and invite via Apple ID.
That way you can access all the content they (or you with their Apple ID) have purchased.
You can decide wether you want to share your purchase history with them, or hide specific items.
You will probably have to download apps and music again —I haven't tried it myself. Please tell us if that is not the case.