Control in one plane

Hello UE4 friends.

I’m a new guy in UE. Just learn it.
I faced with one problem to realize a small level: flat mesh and player control in this XY or YZ plains.
Example… em… big talents table and user can move up-down to serf it.
I tried to use: Physics - Mesh - Mode - XYPlane. Nothing. Character falls.
I removed gravity - nothing.

My question is: what is better way to understand that topic? I mean what should I pay attention?
I tried use: pawn, character with camera + spring arm, camera without character.

I just want to see folowing in ideal:
player moves in one plane by using mouse cursor (no clicking)… or WSAD. Ony in 1 plane like topdown starter example or Puzzle (with moved camera).

I will be very happy if you give me an advise.

In the player character look at the movement component and in the details panel scroll down or search for constrain to plane and there you can set the constraints to keep them moving only on a single plane.