Mark Broadbent shows how to install Docker on Linux Mint:
A web search will almost certainly point you to lots of similar posts, mostly (if not) all of which start instructing you to add unofficial or unrecognized sources, keys etc. Therefore my intention with this post is not to replace official documentation, but to make the process as simple as possible, whilst still pointing to all the official documentation so that you can be confident you are not breaking security or other such things!
You can head over to the following Docker page Get Docker CE for Ubuntu for the initial setup and updates, but for simplicity, you can follow along below.
The installation instructions will also work for Ubuntu and other related variants.