..하고 간다 does literally mean "and go," but in practice it's more like "(do this) before you go." I'm not on twitter, but I'm guessing that online it probably means "select follow before leaving this webpage."
졸예 is an abbreviation of two words. 졸 is short for 졸라 - a bad word meaning "very", "정말." And 예 is short for 예쁘다 - pretty. Together 졸예 means "fucking hot."