someone could guide me, and / or help. because in the game they approved me, the game image does not appear, and how can I modify the 1st place medal?

Not sure what you mean by game image but everything should be in either Edit Game or Add Theme in the sidebar

Make sure you've uploaded these images, they don't appear automatically. If you have and they still don't appear, consider refreshing your browser cache (Ctrl-F5 on Windows). 1st place medal can be changed in "Edit theme".