Yes, you can add text inside and outside a tent card. To do that, you can use one of the templates available on your Publisher version. Just open the program, go to File > New, in the search bar type tent and press enter. Choose a template and the program will allow to add text anywhere you like. To add text, you first need to add a text box: go to Insert > Text Box > drag your mouse to determine the dimension of the box and click to finish. There is no limit regarding the numbers of text boxes that you can add.