How to make animated low poly object

Hi. I really want to make animated 3d model created in Blender. It have basic, one color, simple texture/material, but I don't know how to animate it and add it as block in MCreator. I want to make collectibles like rotating 3d coins, but in a form of block, not entity. Can anyone explain me step by step how to make it? I don't want to use Blockbench, because in it I can create only cubic models, which I want to avoid, because I need to use low poly, not voxel model. I'll really appreciate support, because without it, I cannot finish the mod. I was watching many videos but they are using Blockbench and I cannot find simple tutorial anywhere