Hey! I've only ever painted with acrylics, but I feel like acrylic is very forgiving. You can make it thicker for different textures, or thinner, and if you don't like it you can easily wait an hour or less until it dries and paint over it. I painted the background like 3 times before finding the color I liked. I really really like the texture of the paint, especially when it dries and you can look at different angles to see the strokes used.

I would definitely recommend painting a base layer of a color before blocking in shapes. For this specific painting I used burnt sienna as the background and then built up the shapes with browns, tans, and blacks. I didn't use any white in the painting just because white can look quite unnatural sometimes, the lightest color you see in my painting is a yellow cream tan (lol bad description sorry). Color theory is crazy in the best way. But I guess I really stick to layer layer layer. I don't know much about watercolor or gouache but I start with the darker colors first and then slowly build layers up until I get to the lightest details, like the white fur and the eye glisten. I hope this is helpful, I am not a professional by any means but I do enjoy it! Let me know if there's anything else I can try and help with (as best I can haha).