How can I plan the lesson topics for next lessons?

Select "Timetable" in the mobile app. View your weekly timetable (second view). Select the lesson.

Tap on the Select from the plan and select the topic from the list.

The selected topic will be registered as topic planned. After the lesson it will be automatically marked as taught.

Next steps:
When preparing for the lesson or even during the lesson you can amend your curriculum with notes, images, presentations.
How do I amend my preparations with notes only visible to me?
How to group several cards into a presentation

All materials for the topic can be easily accessed during the lesson:
How do I access my preparations during the lesson