Adding Icon on Left Side to Custom Card

I’ve started down the rabbit hole of modifying the standard/thomasloven cards using card-mod and custom cards so I can get them to look exactly how I want them. However, I’ve never touched CSS/Javascript before so I’ve mostly been copying existing code and tweaking it - but I’ve hit a brick wall.

I’d like to add an icon to the left side of a card (essentially a slightly modded custom card copy of fold-entity-row), like the ones seen in entities cards, so that my cards match. EG:

Icon Example

I’m quite happy dealing with padding/margins/etc but have no idea how to add the icon from scratch. Options I’ve taken a stab at so far:

  • Modify the custom card .js file to add the icon. Main issue is I can’t find anything in other .js files which looks like what I’m trying to mimic.
  • Use the 'style: ’ function from card-mod, however I can’t find any option that will add the icon.

Any suggestions on where to start? Much appreciated!