To use the ladder you should drag BP_LadderBase to the world. In this blueprint you can change the mesh of the ladder parts. You can have as many variations as you want, they will spawn randomly. Now you should choose the height of the ladder. You will be able to get from the ladder if you see an upper arrow above the higher surface.
In the LadderBase blueprint you can change the animations that player uses to get in and out of the ladder.
To change movement animation you should go to the animation blueprint (ABP_Shooter).