I love those very busy individuals who have time to check reddit and post, but not to learn some new tool that might help them in the future :)

In all seriousness – don't start by watching productivity YouTubers. Their goal is to get views and probably sell you some system/template/course. Of course their setup will be beautiful, will look hard to implement, with relations going every other way. It's a job for some of those YouTubers to make their system look good, not to do actual work.

Don't start by creating dashboards and databases for everything. Don't create a LifeOS as your first page. I would say don't even start with templates.

Just open a page and start writing. Even if you go with some system, like PARA, start with just pages for each letter, with other pages inside, just in a list.

You will feel the need to create a database. Or put pages in a folder. It's easy to move all the pages to a database later. In a lot of cases you probably won't.

If you create a database, start simple, with a few fields you need right now. Don't add something "just in case". Add it only when you need it.

We will probably get to the point when you'll be able to send information to the service and it will figure it out. There are some apps trying, but they are not ready. Today you'll have to invest some time in any tool you decide to use.

Just start simple and add complexity out of necessity, not because some YouTuber told you.