Should i say yes to him?? =//?

I have onlyy just been excepted into a new social group at school (im 13!) and this boy has just asked me out. i have made loads of new mates but i dunno if i want 2 go out with him coz i hardly no himm? :// my sister (whos account im using!) is the one who usually gave me all the advice left for america (shes staying for two months!) a minute ago nd im only aloud 2 call her once a month bcoz of phone bills.shud i sayy yes or is hee just jokin to see if im easy or wat? pllease helpp!! xX-Bryony-Xx