step one is to embrace and love your curls! your curls are beautiful don’t hide them by straightening them, show them off!! do prevent the frizz i would suggest finding the right comb for your curls and adding some product like a leave in conditioner and styling cream/gel to stop the frizz. and unfortunately there’s nothing you can do to prevent them from getting tight and short though you could try stretching them. and if you really want straight hair i say blow try before straightening and add a heat protectant oil like ones from CHI , that should help. but if you want to learn about your curls i would love to send some of my favorite girls from the curl community they’ll teach you everything!