How to build a competent connection in the database?

Question

MySQL

There is a Course table It is
necessary to divide the course into parts (frames)
And already in parts there can be different content
Here is an example Course Course
name: How to learn php in an hour?
It is divided, for example, into 2 parts
1 part acquaintance with the syntax
For example, there are 2 lessons that contain the type video
after there is some other text (lesson 3)
well, lesson 4 is, for example, a test
2 part working with the database
here for example Lesson 5 (video in each)
then comes lesson 6, for example, a test,
and in lesson 7, for example, an article and pictures
How to design everything correctly?

Answer 1

3 tables:
1) courses (fields: id, title)
2) course parts (fields: id, course_id, title)
3) lessons (fields: id, id_course_part, lesson type)