The program is going to provide you a Text chart where you can enter the text that you are going to use. Now for the size is depends of what you enter as a number, you can try from 1-1000 and this is going to show you the change, but you just can try find a number that fits on your project. Remember that you need to select from the Tools tab the Text option then on the right side you would have the menu to change the font and the font size.