As a current motorcycle rider I will advise the following:
1.DO NOT ever ride on a ''crotch rocket''. You r like a missle going head first.
2.Always wear a full face helmet. I once got hit in the head by a bird. And wear gloves. Cars kick up little pebbles & stones & when u get hit, u have to learn not to take ur hands off the handlebars.
3. Never wear shorts or sandals or flip flops. If u burn yourself on the exhaust or wipe out & survive, u will have the worst case of road rash u will cry for a month.
4. Always watch out for the other guy, because they never see you. They will change lanes into you, pull out in front of you, turn in front of you, anything u can think of, they will do it. I once had a school bus hit me from behind. The driver was up so high, so did not see down there.
If u pass a safety course, they will teach u to get a smaller bike to start. Do not ignore that advice. When u get better, then move up. You need ur weight to lean into a turn, & if the bike weighs 3 or 4 times what u do, the wind could blow u over the other way.
I know. My bike weighs 515 pounds & I weigh 150. I was on the on ramp to an expressway & a gust of wind blew me off the road into the woods. I was ok, but I couldnt pick up my bike because it weighs too much.
If u start very small, & stay local, wear proper clothing, & pass a safety course, ur mother might go for it, otherwise she has no reason to let u until u r old enough to do what u want. Sorry.