Start by going into the map maker, loading your map and clicking "Export", this will create all the files you need for sharing and place them in "FeralHeart > exports".
If you are on a windows pc, you should be able to right click anywhere and go to "New > Compressed (Zipped) Folder" which will make a .zip folder that you can then put the exported files of your map into. (If it doesn't show up, you might need 7zip or something similar.)
Once you've done that, you can then go to a site like MediaFire or Dropbox and upload the .zip. In MediaFire, When it finishes you can click on it as if you were going to download it yourself and copy the link and share that link with others so that they can download it.