Not trying to put this article down btw, since this was the article that introduced me to gtd in the first place. That said, if you do feel like trying gtd based off this article, I have a possibly helpful heads up for you.
Try out the whole dumping things into an inbox and processing it bit for a short while. Just the bit of building a habit of unloading anything on your mind into the inbox. Don’t worry too much about projects and ticklers and whatnot. Once you’ve done that for a few weeks, you should pick up the book by David Allen and read it. And then implement the rest of gtd.
As someone who tried gtd but didn’t get it for many years, the book has so much context behind the thinking of each concept (next actions, projects, tickler, weekly review, etc). Every single summary of the gtd method feels pale in comparison to that.
Now, everyone’s journey might be different. But just know that if GTD doesn’t work for you after trying it based on a post like this, it’s completely natural. It’s a rare case where the source material is really where all the gold is at.