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.
Templates come in several different formats. You can use a word document or a PDF. You can also download a vector graphic format like PNG or JPEG. Before you download a template, make sure that you're getting a vector graphic.