Click on the Insert tab of the ribbon, and choose Page Number - my preference is to then select Bottom of Page, but you may place the page number as you prefer - next, scroll through the list and select the style of page number you would like to use.
Once you have made your selection, you will enter "Header & Footer mode". You will notice a few things:
- Your document text will appear greyed out
- Your cursor will appear in a demarcated area with a grey tag on the left titled Footer
- There will be an additional ribbon tab (highlighted in green) and titled Header & Footer Tools
On the Header & Footer Tools Design ribbon tab, click the check box for Different First Page.
The footer area at the bottom of the first page will now be titled First Page Footer and the page number will automatically be removed.
At this point you could add a different piece of text to appear as the first page footer, alternately live it blank. Once you have completed customisation of the footer space, you should exit and return to working in the document as normal by either clicking the Close Header and Footer button on the Design tab, or even quicker, double click anywhere on the document outside the demarcated footer area.
Do you have any other Header & Footer related questions? Let me know by adding a comment and I'll create a post especially for you.