Creating a template with fixed text boxes

I am trying to create a template (I think) to be saved as a Word document or PDF and shared with others. The document will have a full-page chart and several places to fill in blanks, that can be saved as a new document. I can save the chart as a background. The problem I am having is figuring out how to create text boxes that are fixed. So far, everything I’ve tried leaves the text boxes variable, meaning any user can change the size or location of the text boxes, which messes up the design of the document. I want users to be able to move the mouse into a text box and type, but not alter the text box parameters. Any suggestions?

Using Writer to create a DOCX is usually a bad idea because the founding principles of both suites are radically different. You won’t get stability through editing sessions and the document will be progressively damaged.

That said, have you considered the form design feature? (instead of text boxes)

I am not aware of “form design” but will look into that.
Even if I can’t share this with others as a word document, it will still be helpful to me. Thank you.