So, a few people have suggested that one of the future exercises should be a walk cycle, which is not a bad idea. I've been hesitant at considering it though because it's the typical thing all animators have to do at some point, if anything the more tricky aspect is giving it personality.

A walk cycle that shows a character's personality may be a future exercise, but for now here are the basic mechanics of a walk cycle.

This video is by Will Hurrell who in my opinion has the most indepth method of how to animate a walk cycle. Also helps that he did it in SFM:
https://youtu.be/bE-jakm9mcQ

This next video by Brian Horgan is a supplement to the first that outlines a mistake that we all make, and how to fix it:
https://vimeo.com/148570430

Hope these are helpful in your animtion endeavours