To answer your question, yes you can make a ladder system in Unreal. My team did this in a recent project of ours so I can walk you through setting this up if you’d like. Just know it’ll take a bit of explaining. For now though, the gist of it is, have an overlap volume on your ladder so when you overlap it you can tell the character to climb the ladder by pressing a button/ key. The simplest way to make the character visually climb the ladder then is with an anim montage, but if you want to get fancy you can define some movement input that allows the character to move up and down the ladder freely, rather than only letting them go all the way up or all the way down.
Again in you want me to go more in depth I will.