Basic Networking Requirements

The basic requirements are a router, WiFi and a switch.  Cheap SOHO routers like the many Linksys, ASUS and so on routers try to do all of these things at once.

However, if you are looking into self hosting, you aren't a typical user and should try for a more sophisticated setup.  Honestly, there's a lot of reasons for having a better setup and that includes not having to replace your router every 6 months, which is literally what I used to have to do in the late '90s, when I first started buying cheap Linksys routers.

Realistically, the ideal minimum network setup would include a router, a WiFi access point and at least one switch.  This will be explained more as I go along.

It will not always be possible but the physical layout of a network should, ideally, be as such.  A centrally located networking room that contains your modem (if applicable,) router, primary switch, primary WiFi access point and servers.  Personally, I have one bedroom acting as a network room and another as my server room because that's just how it worked out for me.  So, don't be surprised if your situation is similarly not ideal.