Datastructure and sub "thing"

Hello,
I am a bubble beginner and I have a little problem with the creation of my database.

I give you an example of what I want to achieve:
I want to create a task creation tool, with users and tasks related to these users.
These tasks are composed of different types of tasks, with different characteristics for each type.
Each task created must therefore be composed of the characteristics of a task (title, description, etc.) and the characteristics of one of the types.

e. g:
Task: Title - Description - Creator
Type-design : Images - URL - etc
Type-SEO: Keyword - etc

Thank you very much for your help.