Welcome to the forum Emma.
You can't get off that easy here. I am also a blond, well before most of it fell out and the rest turned gray

. I will move this to the new to the hobby section so that it gets more readers and maybe gets you more help. Do you have a picture of the pump and filter so that we can figure out what you have and how to advise you?
Edit: Never mind the pictures, most of us know what a Fluval 305 is. It is really your choice what to put into the empty baskets in your filter. Many of us, including me, focus on making sure there is plenty of biological filtration in our canister filters. That means that you stack each basket with ceramic "noodles", those little doughnut shaped pieces, or Seachem Matrix, looks like little bits of white gravel, or even sponges that fit the filter basket properly. Carbon is really only needed if you have medication in the tank that needs to be removed or if you keep bogwood or driftwood in the tank and want to remove the color from the water.