How to add custom settings for Members?

Hello.

I want to add a custom settings-page for Members.

I want the Members to be able to decide which landing-page they want to land on.

So I created a collection called “Members Settings”, in which my idea was that each member would get their own row, and one of the fields would be a boolean, which True = Newspage as landing page(instead of Homepage).

Later I want to add other settings to the same collection, where each member has their own row in the collection to make changes to.

So far I have added a Check-box to the “Settings” Member-page , and connected it to the boolean field. The dataset is set to read-write, and the filter is Owner is Logged in user.
It seems to work if I have submitted once with a logged in user.
But if Im using a test-user, then the check-box is unactive.
So I guess what I want to do is to add a new row automatically to “Members Settings”-collection, each time a user signs up.

Would anybody know how to add a new row to the collection each time a user signs up?
Or
How to have the input-elements (ie checkbox) add a new row the first time they are changed and submitted, and next time the input elements will show the values from the first time it was submitted.?
Or
Is there are better way altogether?

Next, I need a code for how to pull the value from the collection, and load the News-page, if a user has set the value to True.

Appreciate any help, thanks. ( I have only some basic beginners if-this-then-that knowledge of Javascript and velo)

Would anybody have any solution on this?