You are presenting a Google Slides presentation and need to remind yourself of what to...

In your presentation, on each slide, click Insert, then click Comment, and add your speaking notes

In your presentation, add notes below each slide, where it says Click to add speaker notes

Write your notes in a Google Doc and link to that document in your Google Slides presentation

In your presentation, click Insert, select Text box, and add your notes to a textbox below each slide