Why don't you consider working out and dieting that's a most guaranteed way to get rid of fat in your cheeks. You can also do facial exercises. And for the nose, try a nose huggie, it's very cheap, it helps move water in your nose, thus reshaping it a bit. It doesn't work for everybody, depending on what kind of expectations you have. Also make up can help to make your nose appear smaller and it can also make your face appear look skinnier if you know how to apply blush and bronzer the right way. I advice you not to get plastic surgery even if it goes successfully, you'll have awful complications later on in life I promise you that.
Better hope you have lots of money, because insurance won't cover cosmetic surgery, unless it is absolutely necessary, for example maybe for your nose, if you have a deviated septum or something medically wrong with it. Other wise your looking at who knows maybe 20-30 grand for starters.
i don't know about the cheek but a rhinoplasty aka nose job costs between $4000 and $7000. also consider the risks and complications of haveing the surgery. if you google plastic makes perfect episodes online you'll find the slice (channel) website and you can watch episodes of shows free. they have one on a rhinoplasty surgery if you want to watch how its done and risks involved.