This is a pretty typical Ryzen build that uses a Motherboard mentioned on Buildzoid's list as having good VRMs. Check out https://www.youtube.com/watch?v=ti38JS8RuPU or https://www.youtube.com/watch?v=JGY2mqTn2rc
The board I picked has a USB-C slot. If you have no need for that, the MSI B450 GAMING PLUS MAX is pretty much the same board with one more USB-A slot in place of where the USB-C would be. I went with the B450 chipset because this build doesn't need PCI4 and doesn't need the extra lanes provided by X470. The TOMAHAWK MAX board also worked with my 3600 Ryzen out of the box.
The RAM contains Micron-E dies and can run at DDR4-3200 CL14 with timings provided by the Ryzen DRAM calculator "Fast" option.
The HDD is your choice. I went with an m.2 NVME drive but you can easily do fine with a SATA for gaming.
I suggest getting a better power supply. I had this one handy as a spare so I threw it in. But it will soon be replaced with a Gold 650-750W.