It's free roam sandbox, you can explore as you want. But, if you want to go directly to new options to what to do, you can win 10 fights in the arena, talk to your boss, and after that talk to people around the city. A lot of options will open after the 10 win.
Thank you C.M.Cas, I didn't read the page when I downloaded the game so I was slightly confused. I then read the page and was even more confused because like, "How do I do all of this fun stuff?", confusion settled.
Hahahaha Sorry man, my bad for not giving much hints. But don't worry, I just uploaded a new version with a book with hints, and even Isis will give you some suggestions about what to do next. You will be lost no more.