I am 18 year old and want to enroll for Aadhaar card, where should I go for enrolment. Also, I don’t have any document, what minimal document should I have?

You should refer “list of supporting documents” as attached at uidai.gov.in portal in my Aadhaar tab. At least you should have birth certificate if age is below 5 years and any POI and POA document prescribed in supporting document list for age >5 years. You can go at any of Aadhaar enrolment center near you or you can visit uidai.gov.in portal to know nearest Aadhaar center in your nearby.