Apologize for the late reply. This idea is not new and is not easy to set up either. You can take a look at the sample project provided by Epic Games. Or you can observe the vehicle template provided in Unreal Engine. They have a proper vehicle physics setup too and I believe your current setup does not implement any vehicle component and physics rather than just an animation blueprint.
They have a proper setup and examples for you to follow from the template. I know it is a complicated thing and bothersome to do, but it is all a part of the learning process too.
To allow the vehicle to move up and down I will give you some guidance afterwards but first, you have to set up this basic movement.