I bought a program to edit PDF docs but when I open it Im not sure waht to do Fill n Sign??

What program did you purchase? 

Was it Adobe Acrobat?  Fill & Sign in Acrobat is a tool to fill out PDF forms and to sign forms.  There are also PDF editing tools in Acrobat - in the right hand panel there is a "Edit PDF" tool where you can edit the PDF content.

If you forgot the password to your Adobe ID you can click the "Forgot Password" link on the sign in page below the password field on the right.  If you forgot the password to a PDF file you would have to get it from the document creator.

Thanks,

Josh