I did a small tutorial on how to get a free practice space and the size requirements for the vox models in this post:
@nftshowroom/opening-the-nft-showroom-cryptovoxels-parcel-to-the-community-how-to-get-involved

Since you already know how to use Magicavoxel you are ahead of the game, the only difference is for cryptovoxels the models you import have to be one of two sizes or else they won't work! Someone wants to take the gallery around mid december, if you want to do something before that it can be arranged, if not it could be the next one after that, let me know if you have any questions, we have a #cryptovoxels room in the discord too for building chat/ questions etc.