Airborn kicks for martial arts?

well ill b 14 soon and ive always loved martial arts since i was 5 so ive been looking up kicks and stuff on youtube.B4 you start yelling at me you need to know that yes a know that its better to learn from a sensei than on your own by yourself i just have no other way. ANYWAY i cant get into the air for kicks any tips on that? like with a jumping spinning round house kick(i dunno the correct name) and im also having trouble with fluency in turning kicks like a crescent kick,i cant seem to get my leg high enough with all that momentum behind it HELP PLEASE