I think you should find way more, this picture doesn’t really have that much information in it. Look up some drawings of human faces, with highlighted planes, a human skull (or a skull of some prehistoric human ancestor maybe, or a monkey skull), maybe some animals that share similar features with what youre going for. But mostly human, even though this is a goblin you can make most of the structure based on human anatomy.
You can use PureRef to organize all the references. When something looks weird on your sculp, its usually because youre trying to do it from imagination or memory, but the thing is, we dont really know how most things are really shaped 😀 So you need a lot of reference to make something look believable.
