Cannot change font size?

Hello. I have been using the Freelancer theme. I set the font size too large initially. (It’s at 20px.) I want to decrease it, but it appears that I no longer have the same options I initially did when I set up the site. (Dashboard, Appearance, Customize, Typography.) It tells me what it is set at, but I can’t click on it, delete it, nothing. Right below it, it says Add On Available, and when I click on that, it takes me to a screen where it says if I pay $5, I can have access to more fonts, font weights, and font sizes. So am I now unable to change my font size without paying? Or is this operator error? (Totally possible, I am far from computer savvy.) Thanks for any help or advice you can offer me. My site is http://advicefromacop.com