WIFI adapter

Hi, Basically I have to use a wired connection for my work computer at home, but i'm not able to do so with the current 'house setup',; and so i've been using my old phone as a sort of wireless extension lead, which is then tethered to the pc. As I don't use this phone anymore, I was wondering if it's possible to program a file/app that I can install on the phone which will automatically 'engage' the tether to the pc, when it detects it? - The old phone is a Huewei p20 lite and it is tethered to the pc via usb. (No idea if this is possible, but just looking for something unique to save a bit of time - In the case that it is possible, i'm wondering if it's also possible to have an alternating phone wallpaper. If you look at the attached lock screen background, I'm wondering if it's also possible to have it change to and from a black background to the wifi signal background when the tether is disconnected/connected. If that makes sense? Look forward to hearing from you. Kind regards, Rhys