Vw Karmann ghia Stalls and shuts off?

so my karmann ghia is having problems, lately the car has been Driving good without any problems but one day on a red light it wanted to shut off so i give it gas to keeping it on and once i started moving on the green light it began to stall and it seemed it ddidn'twant to respond when i put it in first and second. i cleaned the gas filterbut that'snot the problem i messed with the carburetor throttle and managed to keep it with out shushuttingf but the car is to accelerated and sometimes it lags when i make it run, its not giving the power it used to im thinking the carburator is cloged but im not sure. what can i do or who can i take it to, to carburate it right and get my points to were they should be.? thanks