Ok we still have water pressure in our bathroom tub but the sink and the toilet don't have any water pressure how do I fix this problem

Does the sink have any hot water at all?

Sounds like some mineral build up in the pipe walls broke loose and is now clogging the inlets of your fixtures. Let's take the lavatory first, Shut the water off under the cabinet, open up the faucet and remove the cartridge. Check and clear the inlet ports. Now place a pan over the faucet and turn the water back on for a moment to flush out the supplies. (You should have a strong stream ). Reassemble and test.
I need to know which ballcock is yours.(see image) Back to you. Tom