XnView Software

I'm a new dumb user and simply adding text through the menu is not clear how to make it happen... I want to add it, then size it and position it, but how do I do that.. the help is no help.

You have Edit/Add text

For adding text, you
1 - use menu "Image > Add Text...".
2 - In the "Add text to image" dialog enter your text and set font size, font color, and so on as desired.
3 - Confirm the dialog with "OK"
4 - Move the mouse cursor to the position for adding the text.
5 - Add the text by left clicking.
Done.

I have tried this but can't get the text to change size!! any ideas please!

You can change the text size before you add it to the picture only. Default size might be very small, almost invisible on large images.

To change the text size click the "Choose..." button next to "Font" in Font dialog and then choose the size (you can use also larger values).

You can also use the Paint add-on: Filter » Paint (1.06).
It doesn't allow you to resize the text once it has been added to the image, but it features a preview window.