Just a high school student who is really passionate about film.
This is a really hard question, since both things are kind of essential to filmmaking. If you don't have either of them, get a computer first so that you can edit things, while using your phone or a rental camera to shoot.
If you have access to a computer but don't have a camera, you should just go ahead and get the camera (but make sure it comes with a sufficient storage unit like a 16GB SD Card). You can use the computer to edit and save everything on the card during the process, and upon finishing the film just upload it online.