Congrats on the first time sig! it definitely is not bad for a first, id be lying if i said my first signature was good lol(not that my signatures are all that good to begin with). but i recommend starting out making signatures that follow a theme with colors that match the render and especially with the c4ds try and smudge or blend and also use color overlays on them or gradient overlays so you can make them colors that blend/contrast the render to give it some sort of direction or flow.