Tips: Look up a commercial printer's requirements regarding formatting for submission. Your artwork is usually uploaded to their website. You'll probably open the business card artwork in a graphics program and type your lettering in place, and save as a new jpg file. You'll upload that file and indicate the card stock wanted (like thickness, glossy, and color), and quantity.
Or you can use clean edge business cards, like Avery 5871 or 8871, and print several cards per sheet from your own priner. You'll lay out the images in a word processing program, then print out.