These types of services offer templates for a variety of businesses. They offer templates for letterhead, envelopes, and business cards. If you're looking for a free template, you should be able to find one of these sites.
Most templates for Indesign Business Card Size include the ability to change the line height, color, and margins. In most cases, you will only be able to change the text. However, some templates come with fonts that are pre_programmed, meaning that you will have the ability to select different fonts.