Should i start ballet or jazz?

it is possible to start jazz without ballet, but honestly you won't be very good at it without ballet! ballet gives you proper technique and makes you look good at jazz and other types of dancing. you should do ballet first and do it for at least 2-3 years, yes, this seems like a long time but if you want to prosper in jazz you'll have to have a good foundation of ballet. if it is allowed where you're taking(which it usually is), take both! if not, go with ballet!