How to find a footprint?
I use Eagle and, despite its huge libraries, most of the time I prefer to create my own footprints since I can adjust them to suit my needs.

For example, I usually use a 0.25 grid and the 0603 capacitor as it is on the library doesn't allow a 0.25 mm trace to pass between pads with a 0.25 mm clearance without warnings so I redesigned the footprint so it generates no warnings.

Besides that, it is common not to find the components you need on the libraries or to make slight modifications to adjust them to your design preferences.