@BoltBait Sorry to see you go.
Three basic steps for designing clothes
1. The Texture - What your clothes will look like in the final rendition. (what Paint is used for)
2. The Template - designed to be applied to the 3D object. (Your example)
3. The 3D object - Used to apply the template to make your clothes. This 3d object will be designed/provided by the programmers of the 3D environment you will be playing in. In this case RobLox. Look for a designer pack to download specific to Roblox. The theory might be to create the object in blender, upload to the Roblox platform and apply your template to the object.
This is what I initially started using paint for. I designed clothing for a 3D environment I was playing in. It progressed to other objects like furniture and architecture as well. It was a tedious process, but I was able to create some unique designs for the 3D world I was playing in. The novelty eventually wore off and I haven't designed anything for about 2 years. Seems once I learn how to do something, I don't bother doing it anymore.
It was a lot easier than trying to learn programming. If Rick is the father of Paint you sure were his brother in the progress Paint has made over the years. Just like Red Ochre - you will be back.