15 year USAF active duty here. Welcome to the Air Force! It's going to be a while before your time is free once you hit BMT. I don't know how long it is anymore, I think 6 weeks. You will have no time to yourself, at least that was my experience years ago. I recommend attending the chapel at BMT, not just because of my personal beliefs, but also the MTIs will leave you alone during Chapel. That hour of joy and respite from getting hounded is invaluable.
After BMT, you will go to your tech school, which are all over the US. The enlisted side was still tightly controlled at tech school when I was there, although as the course went on your restrictions were gradually lifted (as officers we were not under restrictions.)
Once you graduate tech school, your regular job will start. Your schedule will depend on your career field and assignment. I have had regular work hours (0730-1630), I have worked rotating shift work, I have worked 12s (more like 13s with change over), and at this point I just work until I have done enough I can go home (that's around 10 hours a day.) Some career fields are more demanding than others (maintainers work like slaves, not so much at finance, etc.)
Remember to keep up with your fitness! Run 30 minutes at least 3 times a week and do daily push ups and sit ups, eat healthy, etc. Also, if you haven't, start thinking about your long term plans. Are you doing 4 or 6 and then bailing for the GI Bill, or are you thinking of staying long term?
When they give you the option, sign up for the 5 percent deduction from your pay for the TSP matching they just started. It's a great deal.
Bottom line, I would expect to get hobby time again once you are done with your tech school, although depending on how rigorous it is, you may get something on the weekend. Your hobby time will evaporate once you have a family. When I was single, even married, I had time. Now with several kids it's basically non-existent (not that I mind, kids are wonderful. Most of the time.)
Feel free to ask any questions.