The point of techniques like the Memory Palace and the Journey is they exploit something you know well. It assumes you have a ready made structure to which you can attach your information.
Every brain is a bit different. Some people have a very strong spatial sense and very strong memories of the physical structures they spend time in. If that’s not there for you then you have to find an alternative.
I am not that strongly spatial. My knowledge of my town consists of a number of travel narratives that I can combine to develop new routes. I notice a lot of people store their navigation information this way - as a process, a sequence of choices. One time I taught myself to play chess without sight of the board, I started with a visual image but ended up with a web of connections.
You need a framework that comes naturally to you. What structures does your mind retain? I depend primarily on stories. Images are important but they are auxiliary, like pictures in a book. When I look around a chamber in a memory palace I hear a narrative voice that guides me from one station to the next. I often don’t have a clear sense of their spatial separation, they appear as a sequence of scenes.
I use drawings a lot. I invent my own, imaginary somewhat fantastical structures and and I sketch them. This way I get something my head likes and the process of drawing forms a strong memory.
There is also the Lukasa idea described by @LynneKelly, author of memory craft, and many other variations. There’s a lot of material in this thread. You might find some useful ideas.