When do you Solo?
Taking off is the easy part, hold her strait, give it full throttle, and gently ease her into the air with a little back pressure, then go into a pattern.
Holding the pattern and landing is what takes practice.
Your instructor should have you practicing lining up with the runway and practicing to hold a pattern, either left or right hand depending on the wind direction. You do this over and over and over, each time reducing your altitude, then, before you know it, your landing and have soloed.
That is where I emphasize the practice, getting your plane lined up on final approach and fly down the center of the runway is harder than it looks, especially with cross-winds and thermals, but can be mastered with practice.
And also remember, altitude is insurance, do not be afraid to stay high when practicing.
One major rule of thumb is to announce your intentions to other flyers since you could be holding up the approach pattern for others to take off or land.
Same goes when you start practicing touch and gos, always announce or have your spotter announce your intentions, it is good flightline courtesy.