To have the slides advance automatically, go under Animations tab and into Transition to this Slide section. Click on Advance Slide and Automatically After. Now, there’s a time set in there and for it to suit your needs, go under Slide Show tab and into Set Up section. Choose the box “Use Rehearsed Timings” and click on “Rehearse Timings”. Now you can tailor your presentation timings to your needs. You can see the seconds pass and after the determined time you need has elapsed, press on either “Next”, which is the first button in the menu and takes you to next slide or “Pause” if you want to pause the timing rehearsal or “Repeat”, which would restart the rehearsal. This time will also be presented in the “Automatically After” Box for each slide separately.