If you absolutely must obtain Reader 11 offline installer from a legitimate source:

: It includes the Fill & Sign feature and basic annotation tools like sticky notes and highlights, which are all most users need.

Yes. Like all versions of Adobe Reader, version 11 is free for viewing, printing, and annotating PDFs. You only need to pay if you want the "Pro" features for editing PDFs.

Acrobat Reader 11 was the peak of "it just works." Unlike the modern Acrobat DC, it isn't cluttered with "Edit PDF" buttons that lead to paywalls.