Increase front size of the First and Last Name sub-labels

2. I need to increase the First name and Last name label located under the first name field.

I think when you are asking about increasing the labels of these you meant the font size of their sublabels which show as hints in the small lettering underneath the textboxes.

To do this easily go into the form designer, click the css tab on the right, then click the sublabel name on the left. You will then see it appear in the css editor.

Now click on font-size in the css helper list and enter in a size you'd like and wallah! Be sure to save the changes once your done.