I just set up a basic next.js app using create-next-app and have been having some trouble figuring out the routing for files and getting basic components like next/link to function. I chose to use the src/app structure when installing it as that was more similar to create-react-app.

1. I noticed immediately that unlike the Next.js tutorial I'm following as well as all of the other resources I see, the main page of the application when generated under the above configuration routes to src/app/page.tsx instead of pages/index.tsx. This is fine, but I'd still like to know why/how this is changed for the future.

2. I can't tell where Next.js is actually looking for my other.tsx files. Trying to open different pages in the way the tutorial describes using the above knowledge (e.g. localhost:port/about to access src/page/about.tsx) does not work and gives me a 404 page. I found this especially puzzling because I can create my own 404 page by creating src/app/not-found.tsx, so I would have thought that it would be looking in the app folder, but placing about.tsx there hasn't worked either.