Depends upon the club (or instructor) and the RC pilot. Different places have different requirements. Some places require you to take off, fly around, and land witout a cord or the instructor taking the Xmitter. If you do it once, you've soloed.
Other instructors and clubs require you to prove you are a safe pilot in the pits as well as the flight line. These instructors want to ensure you are a safe pilot while taxiing, taking off, flying different patterns, shooting different landing approaches, during a touch and go, during a deadstick, during different wind conditions, during landing. They want to see how you can handle an emergency. Flying safe while other planes are in the air. Last training night we had 3 trainees practicing touch-and-goes and landings all in the same pattern. This gave me a good perspective of "airspace" and how to manage it.
So it could take you a day, a week, a month, or a year. I've been flying a year and have about 60 flights on my Superstar, but still have not soloed. In my mind am I ready? No. I want to ensure other pilots in the club feel safe when I am in the air. Can someone learn to do all of these evolutions safely with a simple take-off, fly around, and land for a solo? In my opinion, No. But that is just my opinion, and it will conflict with many on this board.
How ever long it takes you, remember one thing, safety! This hobby can turn to tragedy in the time it takes to blink!
Good Luck and clear skies!!