Wow this is hard to explain, but there is a difference!
So in terms of the verbs... limping is where there is an issue with one leg, so one is okay, and to limp is to walk or move with that specific problem... there's kind of an up-and-down movement...
Hobbling is more of an awkward or odd way of moving - it doesn't necessarily mean there's a problem with one leg.
I know that's not the most helpful description, but I hope it helps! I almost suggest searching for videos to see if you can find a visual example haha... I know it sounds ridiculous, but maybe that's easier than explaining!