The Help:Wikitext page has a list of codes that you can use in order to customise your signature. Since it's just basic HTML, you can also use a search engine to look up additional codes and tutorials to change colour, font, border, add image etc. The possibilities are (almost) endless!
For example, here's my signature: LadyMarbleT/C 16:22, July 24, 2020 (UTC)
Ok. Not sure if I need to do that though. I will probably use my signature on the Wook(Which already has the photo uploaded) and the SW Memes Wiki(Which I have uploaded it onto). Well thanks for the help!