OK Linux can be installed on virtually anything. I would personally put Linux on an external hard drive, USB 3 with preferably 1TB of space on. A majority of USB 3 external drives are backwards compatible with USB 2 anyway. 1TB seems like a lot for Linux, but trust me if you partition it properly it’ll last. I used to carry Linux Mint Maya around on a USB 2 drive 640GB to my local Library’s Internet Cafe.
Use G-Parted you can install it via Synaptic, or the easiest way via Terminal
sudo apt install gparted
Insert your USB 2 or 3 drive and open up gparted.
Here is a video tutorial https://www.youtube.com/watch?v=ZL-qJXztVgA