Although I mentioned using that approach above (using old Linux on old computer)... that is really NOT what you want to do. You want to use the latest up-to-date Linux (whatever distro) if at all possible for the best security, and usually the best hardware support. While an older Linux would still likely be safer to use than Windows XP, it is really a last resort option... which was where I was stuck on that old laptop. UEFI is usually the better choice if you have that option, but if you don't then it doesn't matter. A couple of distros that I would recommend (others may have different opinions on this) are Ubuntu 18.04.1 (MATE desktop) or Linux Mint 19 (again with MATE desktop). These are both the very latest releases and will be updated through April 2023. Mint has several different desktop editions, and Ubuntu has about 7 or 8 different desktops.... these are how you interact with the system, and each has some pros and cons. MATE has a fairly traditional look and feel, not all that much different from Windows, so you should be able to navigate it fairly easily. I also picked Ubuntu and Mint because of your expressed interest in running Steam games.... these two distros should give you about the easiest access to the Steam client as you will find anywhere in the Linux world. (Not that I'm saying it will be totally "easy" because I'm not a gamer and really know nothing of these things, except that they are available in the Software Managers.) Here's a pretty good (and current) article about Steam and other gaming options for Linux. Of the two distros, I like Mint best personally. It's what I use every day, except I have not upgraded to version 19 yet and still use 18.3 which Brian (@Condobloke) already recommended also. Ubuntu and Mint will also both work equally with with UEFI or BIOS systems.