Lots of good info. None of it makes sense to me cause I'm so far behind the world. My tool boxes still have wrenches not gigabytes. Gotta try to catch up a little.
Are you simply looking for a new computer that will be your only device or are you using more than one device, such as a second computer or smart TV?
Do you have wifi in your home? If so the the wifi router serves as your network. You can attach devices to the network either by plugging them into USB ports on the wifi router (faster) or simply using the wifi connectivity (slower but more convenient). It all sounds complicated, but most devices connect easily and come with instructions.
Or, better yet, plug in Ethernet to the router for better speed than USB (except for something like a hard drive)
If you needs M$ Office for yourself and aren't a student on the company isn't paying for it, Check out LibreOffice. It's open source and you pay what you think is appropriate (donation). It reads and writes M$ files. I've often used it to "fix" an M$ file someone can't open (open/save in LibreOffice and then their M$ software can open it again).