You can quickly convert a project from a List to Board view by following these steps
Now you’ll have these tasks show up in both your List and Board project.
If you no longer want the List project and want to work from the Board one instead, you can go to that List project > Click the drop-down arrow next to the project name > Delete project.
All of the tasks will still live on the Board project you created.
Going from a Board view to List view isn’t quite as easy.
I’d recommend you click into each task / card and click the + button (steps outlined above) to add that task to a List project.