You can download webpages easily with any browser as long as you find the right button/command for it.
Just search how to do it, it's simple: "How to download a webpage in [your browser here]"
In Firefox it is dead simple. Just click File Save Page As, then the entire webpage saves to your PC and you can double click it to open it up at any time.
Once you download it, put it on a hard drive or USB stick or just keep it on your PC but make sure your PC stays safe.
Many anons use archive.is to archive things but that site can easily get taken down at any time so it's best to have physical control of the things you want to save.