Since you are so "interested" I would recommend and "entry level" DSLR. Oh my gosh, all those who know me are asking why I deviating from my usual advice to get a good quality "bridge' type camera before venturing into a DSLR. I remember my entry into a SLR (film type) interchangeable lens camera and the only thing was I could not afford either a Canon, or Nikon. Today it is different story. Even though $500.00 is not a drop in the bucket, it seems most teenagers can afford this type through Christmas, and birthday gifts, and perhaps a small part time job.
I really feel that $500.00 or about $550.00 will fill the bill. However I mention a "mistake' I made upon reentering the digital area with a DSLR . It turns out that my manufacturer at the time was offering a "kit" form, which consisted of the camera body, the "normal" 28-to-55mm And a 50-to-200mm lens. And maybe a case. If purchased separately (as I did) you would spend $50.00 MORE! So check out prices before you leap.
Whether you get a Canon, Nikon, or Pentax (I don't recommend Sony), be sure to go somewhere you can handle them and get the feel of viewing through each one (#1 on your list). Then check ot the prices and available size of additional lenses. Also it has been my experience that the manufacturers lenses are better than, Tamron, and Sigma.
Good Luck