Welcome to the forums, Kmeyer93! Looks like your girlfriend's bike is a bit newer based on the V-brakes on it. There is a commuter forum and a mechanics forum that might be of interest to you. Learning how to keep your bikes rolling & shifting smoothly is a great way to enjoy riding more and maybe more importantly in these times, being able to fix your own rides can be a huge money saver. Glad you both are riding; stay safe out there!
John