@Vrai is correct, your CPU is 32-bit. That will limit your distro choices also, but you still should be able to squeeze many more years of use out of it. :)
Hello @Barclavius, and welcome. With only 512 MB RAM, antiX would probably run fairly well, and maybe a couple of other distros. If you would upgrade to 2 GB RAM, as @arochester suggests, it will open up many more choices for you.
That's right, it's sequential. But "joins" is a good word. In geek-speak you also find it called "concatenate." I like to keep commands on separate lines, ending with &&. It helps for troubleshooting. I think a copy/paste of the code below will work in a terminal. You have to enter your own...