What tests do eye places do to you to see if you need gles or not?

im 14 and ive never had an eye test done at the eye doctor..ive never even been to the eye doctor. i have only done the little test at school where you look into this box thing and read the charts. im going to have my mom take me to the eye place in my town because im nearsighted. i cant see far away words unless i squint..could you tell me the tests they do..and if the hurt or feel weird or anything! do they have to use machines or what? also do they put drops in your eyes? please help! im nervous..also if i need gles will they set me up with some right away? or will they like schedule a diff. appt for that?