Nice - I like it. Keep up what you’re doing 
For your game, I am not sure I entirely understand your specific use case so I can only offer generic advice. Quite often in games the developers “fake” outcomes. If you want to have a wheeled cart that you can push around, create an actor that you can only move along the XY plane. Then add “wheels”. You can setup rotation speed on the wheels with the RotationMovement component based on forward velocity. That way the wheels will rotate with variable speed depending on the speed of the cart, but it will not be 100% pure physical simulation. It will look like the cart is moving on its wheels so you get the right outcome but without complex physics simulation.
Otherwise, you can still used wheeled template to learn how to create a wheeled vehicle. Just don’t apply any throttle/steering and it will behave like a dumb cart.