[toast0]

> plugging in the computers to the wired network is a good free first step

Plugging into wired ethernet is only free if you have a wired port near the computer and it connects (properly) to an available port on a network switch and you have patch cables onsite and free labor to connect them (including labor that can access the network closet if needed) and free labor to configure the computer to prefer the wired over the wireless, if necessary.

Ideally, it's not a lot of labor, and there's likely to be some switch ports available and some patch cables available, but there's also probably a reason the computers are using wifi if they are.

You can argue this is probably part of someone's job already, but if they aren't doing it because they have too much other stuff to do, you'll need to pay someone else to do it.