I need to use the NINA-B306 module that is used on the Arduino Nano 33 BLE Sense for a project but I am unable to find a schematic and footprint to use in EAGLE for designing the PCB. Arduino provides the EAGLE schematic and board file for the NANO 33 BLE Sense so I assume one must exist somewhere. I usually use SnapEDA for this kind of thing but they don't have a schematic for it and the footprint they provide is incorrect. If there are other websites you recommend besides SnapEDA please let me know! I'm relatively new to designing PCBs so any tips on where to find this information are much appreciated.
Have a look at KiCad EDA. It is a open source PCB design software with a large library of components and footprints. I really like the fact that you dont need to decide which package you need when you create the circuit. You assign the package/footprint separately later.
Additionaly check out the "Contextual Electronics" YouTube channel. They do a really nice and short explanation of how to get your own PCB including getting your own footprints and schematic symbols.
I have not tried version 5 yet, but creating a circuit and board with version 4 was easy and fun.