How to attach a collision to a 2D character so it moves with the character .
And i want to ask an other question which i didn’t a good answer for on
What is the difference between a mesh and a sprite
Hey ,
If you take a look at our 2DSideScroller Template, you can actually look at the character in there and see how it’s set up. Basically, you’d want the Collision Component to be the root, and the child of that would be the Sprite. Here is some information regarding [UE4 Sprites][1], [UE4 Skeletal Meshes][2] and [UE4 Static Meshes][3].
Basically, the Sprite would be the Paper Flipbook Component, which you would want to use for a 2D Paper project. If you wanted to use a Skeletal mesh, you’re looking more for a 2.5D game or a 3D game, because the Skeletal Meshes are used for 3D models typically.
I hope this information helps clear some questions you had regarding the difference between Mesh and Sprite.
Have a great day! 
Paper 2D Sprites in Unreal Engine | Unreal Engine 5.1 Documentation
[2]: Skeletal Meshes | Unreal Engine 5.1 Documentation
[3]: Static Meshes | Unreal Engine 5.1 Documentation