Click anywhere on the Header area on your form and the 'Form Properties' tab will open up on the right sidebar

Select the title and subtitle and you can change the font type, font size, text color, text alignment in the header as you wish under the Form Header settings

You can change the size of the title or the subtitle

You can change the color of the title or the subtitle

You can change the font type of the title or the subtitle

You can select how many columns you want to have in your form

You can change the font type of all the fields on the form with the Form Font Family setting

You can choose to show your company logo that you uploaded before by using the Show Company Logo setting

You can set activation and expiration dates and times for your form

And finally, make sure to save all the changes

Click "OK" and you set all the general Form Properties as you wish!

How to Change Form Properties