Welcome, Greg. Glad to have you as a member. I'm going to step in and state that it would be highly unlikely to find a C-150 for $15,000 that would not kill your budget in the next several years with needed work.
Remember, the price for planes is set by people who have owned one or more planes before, and their experience tells them that a $15,000 C-150 will need many thousands spent to bring it up to what you can buy for $20m to $22m. Otherwise, the seller would be asking $20m to $22m which is what a good C-150 should go for.
I would strongly suggest waiting until the Fall when you have more financial capacity, and more experience in several aircraft to see if a C-150 would be your choice. We love them for our missions, but it just might not be the bird for you.
As others have suggested, do have an experienced member of the Club help you look at any plane you are getting serious about, and have at least a pre-buy inspection (I actually recommend an Annual inspection. Those have written standards. A pre-buy doesn't, and can be anything the A&P decides it to be. I know of a plane that received a pre-buy from a shop that then grounded the plane two weeks after the purchase during an Annual).
Don't rush into buying. Enjoy paying for rental rates knowing that whatever breaks is on someone else's dime. Planes aren't going up in price (in fact they are going down). Relax and enjoy getting your license and experience. This Fall will come soon enough.
Take care. Mike.