There are probably tutorials out there … you would have to probably search.
Not sure why you are against buying a blueprint kit … this is one of the ways I have learnt tons and I have supported my fellow developers in the process. I actually bought a pack this weekend and found a good way of not doing something.
So I don’t think you should knock that option just yet. Failing that … try a “Google” search for “ue4 ledge climbing” … I found quite a few links there.