A few years back I started to try to use my computer by not touching the mouse. Ended up writing a bunch of Tampermonkey scripts for my most used web pages to add fast keyboard navigation shortcuts.

Also a lot of webpages have it already built in, by pressing "?" they show a nice overlay. For example github and gmail have it.

For github I still ended up adding a quite a few more shortcuts.

You can always take it to the next level by using an extension like vimium[1].

[1]: https://github.com/philc/vimium/