I don't know my range of singing. How can I figure out what range I am. ALto tenor soprano?

If you're a girl, your choir director will not let you be a tenor, you'll spoil the section. All you have to do is go on the piano and sing along going high and low. If you have a hard time getting below Middle C and you can hit a G above the staff, you're a soprano. If you have a hard time getting above a D on the staff, you're an alto.