Guys I truly don't mean to spam the community but these are legit questions. Yesterday I posted about linux compatibility and computers and every single person gave me knowledge to use and you're all awesome.
Now my question is, I will undoubtedly be purchasing an older machine, would an older but good running machine still be able to install the latest kernels or versions of distros or are you limited to older versions only, based on the era of your laptop or is it really about the hardware you have? I know ram, disk space, basic stuff like that matters with distros, but I know that will not be a problem. I guess I'm thinking beyond that like processors. are older processors or anything else hold certain machines from being compatible with the newest and greatest kernels? Thanks!
I second that about Nvidia GPUs. While Linux hardware support is really good, there is plenty of common, mainstream hardware that never was and never will be supported by Linux, usually due to uncooperative manufacturers. For Nvidia, their non-free driver is terrible and the nouveau driver in Linux is hit-or-miss. (Note, many people use either of those successfully, but the likelihood of success drops rapidly with any of: multiple displays, the need to dynamically change outputs, multi-GPU Optimus hardware or even laptops in general, and fully functional hardware acceleration.)
While one should, ideally, use AMD over Nvidia with Linux. It sounds like OP is shooting for older hardware, so I'm going to assume GPU performance isn't a significant consideration. Nouveau should be fine for regular desktop usage on older Nvidia cards.
But trouble with assumptions. If you do want the most out of your GPU, AMD is the way to go.
Sounds like OP is more likely to have a winmodem than a Nvidia GPU that doesn't work with nouveau