I was in your shoes when I was in poly.
Now my friends ask me this qn, I know how to answer them.
Get a mid-range APS-C cam.. For Canon, 70D or 80D. Pair it with a Tamron 17-50mm f/2.8 as a kit lens. Get a 50mm f/1.8 lens.
It will be good for a start. If u need telephoto, rent the 70-200mm f/4...