I do not recommend doing much of your private solo.
Most my students have 10-11 hours of solo (minimum is 10 hours). Usually they have about 6 hours of solo xc, and another 4 hours of solo TO's/landings.

Practicing maneuvers is best done with an instructor on board. They are there to find your faults, bring them to your attention, and make yourself a better pilot by learning from those mistakes. Even if they aren't there to coach you (eg. playing examiner), they can still debrief you at the end of the maneuveras.

My advice is get your instructor and go for an hour of practice doing power on stalls. I don't recommend doing any of this solo. You just don't learn anything.