Some "distros" are more user-friendly than others. Some are designed to work as closely to Windows as possible, to make the transition easier. As an example of both, I use
Linux Lite. It is based on ubuntu, the most widely-used distro, which gives it a ton of support and makes installations of most programs very easy. It's a full-featured OS, and only light in its need for hardware resources and in its learning curve.
You can look for a machine already loaded with Linux, or you can install Linux yourself on an old or new machine, or have a friend or a shop install it for you. Linux Lite is very easy to install, and has a very nice Help file onboard, and online support forum. Since Linux is generally lighter than Windows, it works great on older (and cheaper) hardware. My main machine is a converted Vista-era tower, and it works fine. Updates are a snap, and the privacy factor is much better than Windows. And generally, there is no need for an anti-virus, which frees up performance a lot.
I've converted several friends' machines, and a couple of units that I sold, to LL, and all love it, and most of them say they hardly can see the difference from Windows in terms of usage.