Newbie question - Working on scanned image -

Hi,
I'm new to photoshop. I've a scanned image with text (jpeg format). I want replace the text and some part of the image. How should I proceed?
Thanks for ur help.

Duplicate the image and work on the duplicate layer. Erase any parts of the picture you don't need. Fill in missing space with your amendments.

Bear in mind that the text and other elements are just a flat picture and are not directly editable, other than by deleting the portion you do not want.

Or by cloning over those portions.