I too found the installation screens a little confusing but this is what I did.
The first installation folder question I took to mean where the temporary install files would go, so I created a new folder for this. After answering that question I got a similar, almost the same question, which I took to mean where do I want to install the sim to, so I created a new folder e.g. D:\FS2020 and after the install completed that is where it had installed to.