To answer some of those questions.
If starting out and just trying HA to see if it suits you, install it on some hardware you already have, it will install in a VM on most hardware. Always do this before buying dedicated hardware you may end up not using.
Nowadays a basic HA setup is easy, and requires very little programming. The great thing though is as you progress you can learn to do more complex stuff if you wish to.
Most IOT stuff is wireless with no option to hard wire, although most once setup are pretty reliable.