I agree with starting with what you have to get learning, but I wouldn’t run a Minecraft server on this machine. I’d start with everything else and then buy an old office machine to upgrade. It depends on the unit, but they are easy to upgrade basic upgrades like adding RAM, storage, and possibly a low power graphics card. Since most servers are always on, keep an eye on power consumption with a power meter.

Most carriers know your name, your internet usage metadata, and your location all the time using cell tower triangulation. There have been multiple reports of phone providers selling location data and sercurity breaches. If you have a phone that provides MAC address randomization and you use a VPN then I think using public WiFi is more private than having your mobile data turned on all the time.

I have my phone on airplane most of the time and use Wi-Fi with VoIP for calls and SMS. If I need mobile data, I have a Silent Link eSIM for mobile data only. If you ever need to make an emergency call you don’t need a sim card or provider, emergency calls always work. While the main motivation is privacy, it’s nice that it olny costs about $3 per month on average.