A good ortho will more than likely have more resolution than you need or will want to bring into an editor. You’ll want no more than 300ppi and probably only about 200ppi for enlargements viewed from a distance. Then, just use an image editor to make it look it’s best. Then print it at Costco or similar. Very cheap. When you think you’re ready, you could send a small version of it to be printed at like 8x10 for almost nothing and see how the color and contrast look. If they’re good, print to your desired size.