Simply click the "Plan 1:1" button for the person that you want to meet with on the "Meetings" tab.
Alternatively, you can search for a user via the search bar and click the "Plan 1:1" button on his / her profile.
In the "1:1 meeting" window that opens, you will see a section to add talking points, a section with talking points of your counter-part and a section to write a meeting summary.
Start adding talking points: Talking points are things that you want to talk about during your meeting. For example, you could add things like "Discuss the budget", "Plan a team event" or "Review marketing material". You can define whether you want a talking point to be private (visible only to you) or shared (visible to you and the person you're meeting with) - sharing talking points allows you to create alignment even before the meeting. Obviously, you can edit, delete or re-arrange these at any time.
Customize your meeting structure: Sometimes you want extra structure for your meetings - you can therefore add sections or questions (such as "What are current road blocks?") to guide your meetings. This can either be done for each meeting individually, or - if you are an admin - in the admin settings for the entire company. To change the structure, click the "Meeting settings" button, scroll down to "Customize meeting structure", add your sections / questions and save your changes.