A:Answer You still need most of the internals. Think of this as a car frame and you you still need gas tank, transmission, engine, etc.
A quick list of what you need.
Motherboard
Processor
Ram (memory)
Hard drive or solid state drive
Power supply
Video card(GPU) if your processor doesn't have a built in one or you want to do more intense programs such as modern games.
I hope this helps. Personally I would look at AMD motherboard/processor setup. The 5700g processor and the x570 motherboard if you don't want the extra and currently expensive cost of a video card. 16gb(2x8gb) is sweet spot for ram