How can I resize the fonts? It is little too big.

You can change your font size by following this guide: https://www.jotform.com/help/186-How-to-Change-Your-Form-s-Font-Size. 

That guide will help you on using the Form Designer Tool, if you want to learn more about the this Tool, you can check this guide: https://www.jotform.com/help/300-Form-Designer-Tutorial-Let-s-create-fantastic-forms-. 

I hope that helps.