I was going to do a filter but when I searched it I found that I needed Color Dodge. How do I get to it and what does it do exactly?
Color Dodge is a built-in "filter" (Blend Mode). See below:
Select the layer you wish to apply the effect to in your Layers Panel and click on the circled drop-down menu:
Choose Color Dodge
Adobe explains color dodge on their site as:
Color Dodge Looks at the color information in each channel and brightens the base color to reflect the blend color by decreasing contrast between the two. Blending with black produces no change.