If you want to install Linux on a desktop, you'll first have to create a bootable USB drive with your distribution of choice.
Linux has evolved into one of the easiest operating systems on the market to use. The GUIs are (for the most part) so well-designed that anyone can use them. And for those who might be afraid of having to use commands. those days are long past.
Sure, if you really wanted to make the most out of the raw power that comes with Linux, you could make use of the command line, but you don't have to. That's the point.
If you're looking to revive that aging laptop, Linux might be your best bet. Find out how easy it can be to make this happen.
Linux has been my primary operating system since 1997. When I first started using the open-source OS, it was not easy. There was a lot of command line work to do and keeping my 33.6k modem online was a nightmare. With some serious persistence, I made it work and eventually made a career out of covering Linux and open-source software.