Editing A Sprite
Even without running your own server, Amalgam Engine worlds let you do some local art modding. Other people won't be able to see your changes, but it's a good way to dip your toe into working on a world!
1. Finding a sprite to edit
In the world folder that you downloaded previously, look for an Assets folder. Inside will be a Textures folder that contains all of the world's sprites.
Look through the sprite sheets and choose one to edit. Ideally, it would be one that you know how to find in-world.
2. Editing the sprite
Make a backup of your chosen sprite if you'd like (make a copy and name it something like "name"_old.png). Then, open your chosen sprite in an image editor, such as Paint.NET or GIMP. Make some changes (recoloring is usually pretty easy) and save the file.
3. Viewing your changes in-world
With the file saved, connect to the world and find an instance of your edited sprite. If all went well, you should see your changes in-world!