actually how long it can't be a reference, in my opinion the knowledge of crypto, a friend who is experienced in crypto has an important role to make you become a professional. Your totality in studying Cryptocurrency will focus your concentration on becoming a professional.
If you're passionate about cryptos and have enough time to learn and practice it won't take you long to become a pro. I guess year will be enough. But remember that crypto world changes rapidly, so you'll have to learn something new all the time to stay a pro.