Yes, once you are a U.S. Citizen you will be able to sponsor your parents for a GC. The process will take between 6 months to 1 year depending of the consulate location.
If you just want your parent to visit you but not obtain a GC for them, they can apply for tourist visas. Although your parents will have to qualify for these visas, the fact that you are citizen will increase their chances.
Good Luck,
