Welcome from Maryland. I'm excited for you! I can tell you're so eager to get started, and why not! Besides a cutting mat and rotary cutter, do you have an acrylic ruler? Ideally the best one to start with, I believe, is a 6x24 inch one. Since the hobby gets expensive, that size willbe sufficient for many different sized pieces you need to cut.
Another tip, buy the best fabric you can afford. Quilt shop fabric is high quality. You can really feel the difference compared to fabric from Joann or cheap stores. Hold the fabric up to the light and notice the difference in weave and color saturation. I'd practice on cheaper fabric, of course, but once you decide to make something you want to keep or give away, buy good quality. It holds up to washings over the years, doesn't stretch out of shape, and feels so good.