Switching Formula

My LO is 2 mos old and on the Enfamil Newborn Formula....my pediatrician said I could start on the Infant version. I am wondering though, can I just switch to the Similac infant formula? I wanted to try the non-GMO and they sell it in bulk at Costco. We attempted BFing but my son has a tongue tie and the pediatrician didn't think it was significant to act on it so we switched to formula. Tried pumping but I had no supply. Any FF moms have advice? Thanks!