New to Web design

So i was thinking to myself about how profitable betting sites are and what a viable market video game items are and i was wondering the best routes to go about learning more than basic web design and how i would even begin to go into all of the account linking and complicated market and database building i would learn to do. I know enough python and java to get by and am in the process of learning Mysql and everything Linux. Any information would be appreciated greatly. Thank you.