I currently have 3 3D Printers, 2 Standard Plastic Extrusion, 1 Vat Laser Polymerization. I used to use Thingiverse, but now I just design stuff using a 3D design program called Inventor. Much more useful to learn how to use 3D design programs than to print other people’s designs, as they often can be flawed, and you may not find the file you are looking for.
As to why your printer messes up so often, if it is a standard plastic nozzle extrusion, try applying glue from a glue stick to the printing base. Helps it stick much better and messes up a lot less often. Or the model you are printing has too sharp overhangs. It depends on the printer and filament, but when an overhang is 45 degrees or more it will mess up, to prevent this use a printing object support setting, which auto prints supports onto the object which are designed to easily break off once done printing.
