1) Are you sure you're running the most up to date copy of the report in the application?
The default behavior for the report header and textbox is that they are visible unless specified otherwise.
2) If the report header is being suppressed, it will appear as a darker shade than normally visible sections. If the report header looks to be suppressed, you need to check the Section Expert for the Suppress checkbox associated with the report header section (it can be set conditionally - kill the button next to the Suppress checkbox to see if there's any code. Generally the button text is red if there is any conditional logic).
3) If the report header is visible with no interference, check the suppression logic for the texbox - right click on the textbox, click properties. Same checklist as for the report header.