You need to know your exact time & place of birth. I use astro.com it has great free natal charts. The interpretation is the difficult/expensive part. I'm an amateur astrologer and I can interpret the major aspects pretty well but I still have a LOT to learn about the nuances, which are many and detailed! It's fun though, I like to do cold readings bc that proves it best. I do think there is a psychic component and the best astrologers are psychics. I'm not a big fan of computer interpretations of charts and find them less accurate.
If you ever just want to get started learning the basics, I love Linda Goodman's astrology books. She's very good at conveying/describing the qualities/energies of the signs, planets, etc.