Hello. The sprayer on my sink works and sprays both hot and cold water, but the regular faucet doesn't. Any advice?

Take the aerator off the end of spout and clean mesh screen, then reinstall. Run water out of faucet with aerator off also.

Most of the faucets with a spray attachment have a diverter valve in the valve body where the spout connects to. You must remove the spout assembly. Now, is this a single handle or two handle? In any case you need to disassemble and get the spout off. Then you will find a hole with a brass and rubber gasket. Remove both and you'll find rust and debrie. Clean and reassemble. That all there is to it. Post back if more questions are needed