How to expand text boxes in Pages application

WARNING: Rookie Mac user. We moved from Microsoft Windows to Apple and did it cold turkey! For our business we have always used Microsoft Publisher to create .pub files and then convert them to PDF documents. These became a digital proof we emailed to our customers. For days we have been trying to figure out how to expand text boxes in the Pages app so the text expands to scale. I'm not talking about increasing the font size.

For example, in MS Publisher, you can mouse over any corner of a text box, grab the corner and move it outward or inward and the text will expand or shrink. I have a trial copy of Adobe InDesign and I know you can do this by clicking the command key while mousing over any corner of a text box. I can't seem to figure out how to do this in Pages (or Swift Publisher for that matter). Adobe InDesign is too complicated and way more than we need for what we're tring to accomplish...and it's very expensive.

Basically, all I'm looking to do is this:

1. Make a solid black background

2. Insert text so I can expand and contract the text box while the text expands and contracts proportionately.

3. Convert to a PDF.

Thanks,

Adam