Text Edit Box won't Open in Photoshop Elements 2023.

@marilynfenn, are you saying that editing in the text box used to work for you but now it has stopped working?  Or are you asking how editing text works in Elements?  Can you please explain in more detail what you mean when you say the text box won't open.

You say that you can edit the text in the box.  Are you talking about the layer name (that by default is the original text that is entered with the text tool)?  If you double-click on the layer, the text becomes editable.  BUT, all you are doing is changing the name of the layer, not the contents of the text you have added to the image.

To change the color and size of the text in the image:

1. Select the text layer and double-click on it. 
2. This should select all of the text in the layer and the selected text will change color to show what is selected.
3. You can now change the color and
4. The size and/or font of the selected text in the text tool options panel

Note that changing the text color will result in the selected text changing color - but not to the chosen color until you deselect the text:

You can now single-click within the text box and an editing cursor will appear.  This allows you to edit the text itself.

Once you have completed your edits, click the green checkmark and you are done.

Now, I'm sorry if you knew all of this, in which case, if the text tool is not operating as I have described, I suggest you reset the preferences file. Go to Edit>Preferences>General tab and click the Reset Preferences on next launch button.

PSE is not a text editor. The most pragmatic solution for your purpose is to delete the text layer and create a replacement with color and pt size to suit.

@marilynfenn 

I've moved your post from Photoshop to Photoshop Elements for you.

Jane