How to sing high notes without screaming/Squeaking?

i am 14 years old i can sing very good like monica and jennifer hudson somewhat...but i cant seem to get the high notes and i live in a very small town so there are no vocal teachers here...it's like when i sing and i try to go higher (not like mariah carey) i star screaming or squeaking PLEASE HELP i really need to learn because i want too become a singer and my first step is too perfom in front of my parents and i just need to learn how to sing those notes.... NO IGNORENT ANSWERS PLEASE I AM VERY SERIOUS AN WILLING TO DO MY BEST TO PERFOM AT PLACES FOR MY START ! answer where i can understand it please. Thanks !