Use Photoshop's text editor; select the tool with the letter T. What is the file format of the file?

Illustrator would be a better program for that purpose. From Illustrator you can switch to Photoshop if desired after editing the text. Though Illustrator works well with PDFs. So you might even look at converting your document to PDF if you have Illustrator.

Keep in mind Photoshop creates raster graphics using pixels, while Illustrator creates vector.
Photoshop's Text editor is one of the few tools of Photoshop that deals in vector graphics.

I suppose I should also ask the question why did you wish to use Photoshop for the purpose?
Your thread title is Editing a photo, so I am wondering what you are trying to do?

If the file is MS Word document, then one option to try is to open the document in MS Word or other text program, select the text, copy and paste into a Photoshop document after selecting the Text tool.