What you need to do is take J bend off trap and go to box store and buy a small twist cable and run it dow n pipe and clean it out. If you cant do it call a Lic. Plumber to take care of it. Let me know.
Most lavatory blockages are a combinmation of hair and grease. This can build up on the stopper and restrict drainage. Let me give you instructions on removing the stopper. If the stopper won’t pull up then the installer tied it down. To free the stopper, push down on the knob raising the stopper to the drain position. Now go underneith the lavatory and locate a knured nut with a rod sticking out of it. Take a pair of pliers and free the nut just enough for it to turn by hand. STOP! Now hand loosen the nut enough so the nut and rod just begains to clear.