The best place to see what works is the F4PGA examples documentation at <https://f4pga-examples.readthedocs.io/en/latest/building-exa...>.
If you want to start with fully open source tools on a Xilinx 7 series FPGA the best option is the Digilent Arty A35T board <https://digilent.com/shop/arty-a7-artix-7-fpga-development-b...>.
They have a lot more IO available, but they're also out of stock until the chip shortage problems improve...
They have a lot more IO available, but they're also out of stock until the chip shortage problems improve...