Tacpot is right. You are allowed to fly solo away from the airfield (under the supervision of your instructor on the ground), but there is not much to be gained from it at this stage. You will have plenty of time for that later!
I doubt your next flight will be solo. Possibly a couple of circuits with your instructor, then a couple solo. You will spend more and more time solo in the circuit, but I do not recall leaving the circuit solo until the Navex. Incidentally, I found my first solo away landing even more rewarding than first solo.
Did you notice the amazing performance improvement without your instructor onboard? The rate of climb (in a C152 anyway) was quite a surprise.
TG.