its good that ur going to be buying a guitar..in a way be glad u started with acoustic..u will hear ur mistakes bette ron accoustic than elected.. i believe the pickups are used for picking up the amps signal or somtihn.. and a scale is an ascending or descending line of notes..there more to it but i dont know much theory.. alternative picking is just taking the pick and picking in up and down motion over and over and over agin..