Using an electronic signature when filling in a form

I am an Adobe Newbie, and and oldie.  Please help!

I want to use an electronic signature to fill in a form, rather than print it, sign it, scan it, send it.  I have the full creative cloud all apps package, but when I try to use a signature it directs me to the free trial. 

How do I put in a digital / electronic signature when filling a form in Acrobat?

Help much appreciated!