Do i date him or is he just using me

what do i do, there’s this guy who says he really likes me and doenst talk to any other girls and he really wants to start dating, but whenever i comment on his insta he just replies to me the same as everyone else. And the worst part is i don’t wanna get awkward with this guy cause it’s one of my friends first cousins, i’m so confused about what to do. he’s really nice and all but i’m only 14 and the other day he was like to me, would u ever like get dirty with a guy and i said idk and then he asked would u date me and i was like i guess but i wanna know u a bit longer. once i said that he got kinda pissed with me