A content plan is a document that serves as a guide to define your brand's content strategy. In this file, you will specify objectives, frequency, and methodology.
How to start creating the content plan for your social media accounts?
Turn off your cellphone.
Serve coffee or tea.
Play your favorite song.
Write down all the ideas you can think.
List the problems of your target audience.
Write a minimum of 30 ideas and repeat the process.
PS: Notion is a tool I like for brainstorming sessions and making a content plan online.