In the resource blueprint you can change settings such as the random sizes of the mesh and resource amounts. This can be found in the Class Defaults of the resource blueprint like in the image below of the BP_WoodResource.

Min Mesh Size & Max Mesh Size – This is the min and max random scale of the resource mesh.

Use Random Size & Use Random Rotation – These settings enable the use of the random mesh sizes and random rotations of the mesh when the resource is spawned in the level.

Use Random Rotation X ,Y, Z – Only used if Use Random Rotation is ticked on this will cause the resource mesh to rotate randomly in all directions when spawned.

Full Resources – This is the number of resources each resource has to be collected by units.

Resource Icon – This is the icon that will be seen when the resource is selected in game.