can my aunt be a legal guardian of me though I am 20, and don't have special needs ?! if we do all the paper work required for legal guardian ship

In order to do a guardianship, a person is found legally incapacitated, I don't think you want that.  You are an adult, you can choose to live with your aunt, or you can give her a power of attorney so she can help you or she can become your conservator, but if you are not developmentally disabled, have special needs, or some other issue that renders you incapacitated, you should not do a guardianship.