RE: slide master
Hiya Abby
Hope you are having a good day??
You can insert or use a slide master when every you need it, if you are not sure what this is the slide master is used as a template of your presentation so anything you insert on your slide master will appear on all your slides, so in essence you dont need to insert a slide master you just go to the master and make changes to this
The way to get to the slide master is by going to the view menu, then choose master and then click slide master
Please be advised that if you type any text in the text boxs this will not apply because its just the aesthetics i.e. the way things look
hope this helps
Mark East