Editing styles - where do you even begin?

Want to set up Zotero to speed up and simplify my referencing, but my university using a modified version of Harvard referencing that's not included in the 10,000 styles, and I've not been able to find a CSL file online either. Took a look at the style editor thinking I could modify Harvard myself to match and holy shit what is going on. I've never done anything that involves code, is there an idiot's guide or something I could make use of?