What are art schools looking for from high school students to have completed in a portfolio.?

I am a high school sophomore looking for help and suggestions as to how i should continue my art education. Good at oil and acrylic painting as well as pencil and graphite.

Went to the art institute, they have schools all over. Plenty of talented people there (though some are a just a joke)… they interview you but you dont need a portfolio but it is a plus if you do have one.