can I sell my car if it's being financed?

Yep then your upside down in your new car. If you can find someone willing to buy the car from you by taking over the loan you will be in a better position to purchase another vehicle but you have one of those "do not buy used" vehicles. Best of luck too you.

I'm assuming you're not shopping at new car dealers. Any new car dealer should take your financed vehicle in trade. They pay it off and add that money to the cost of your new vehicle. So you wind up paying for two vehicles, one of which you no longer have. Smaller used car dealers don't have the capital to do that. So, shop for a new vehicle at a new car dealership. But, unless your current vehicle is falling apart you should keep it until it's paid for. Then trade it in. If your current vehicle is falling apart and you're not shopping for a new vehicle at a new car dealership you're just trading junk for junk! Jim