If you can't or won't delete a project that you didn't create, you can leave it.
You won't be included into its participants and it won't appear in your list of projects anymore.
To leave a project, you have two possibilities:
- Menu bar on the left > Project name > Click on the 3 small dots to the right of the name. A menu opens, click on "Leave the project", then confirm or cancel.
- Project > "Settings" icon at the top right of the project window (below the user drop-down menu). You access the project settings. Go to the "Collaboration on project" section. Below the list of members participating to this project, click on "Leave the project" then confirm or cancel.
Note: If you want to have access to this project again, you will have to ask someone on the project to share it with you again.