I just picked a place holder case, choose whatever case catches your fancy.
The ryzen 3600 is afine cpu, and the stock cooler works fine as well, but if your average room temp is higher or airflow is lacking, it's best to go for a budget cooler with it. You could also go with a ryzen 7 3700x instead and use the stock cooler that comes with it, that stock cooler is half decent.
With ryzen cpu's, you will need to pick fast ram, 3200Mhz is the minimum, you then will set up the speed and timings with XMP (Extreme Memory profile), you can look up many videos on how to do this. The memory will default to either 2133 or 2400Mhz if not set up, costing you 10+ fps.
The corsair CX or TXm power supplies are the minimum I would recommend for this build, if you can find a corsair RM650x or Seasonic Focus Plus for around the same price, you'll be good for the next 10 years and any future upgrades.
If you're patient and don't mind handling potential driver problems, the amd RX 5700xt is both faster and cheaper then the RTX2060 super/2070.