Look at the whole query that you get when you use your first injection. The 1=1 evaluates to true, but you are still left with the LIKE ‘r’. That’s why you don’t get anything, there is no username that consist of only a single ‘r’.
As for the second injection, it doesn’t work because those functions are not available for this server. There are multiple types of server and all have different functions (and syntax). It’s a good start, though. Keep playing around.