Gonna chime in because I agree with the posters in saying please reconsider doing this event at your stage in training.
Solid spins and circles of differing speeds are not something you pick up in 20 rides. Not balanced circles or nicely planted spins that is. Does your newly broken horse have sliders on? Have they had sliders on the entire time you've been breaking them and working towards the slide you already have? Please please do some more homework (and not just on a forum!) before showing this horse.
Is this possibly a green horse freestyle class? I haven't seen one personally but I supposed it's possible...
ETA: is this the horse you have questions about riding in a curb bit??
Typically it will take about 20-24 months from start to finish on a reiner and that is with the trainer riding the horse. The fastest I have had a horse in the show ring was 8-9 months at that point if she had been shown in a snaffle she would have done very well. As it was she was being shown one handed and needed a bit of help about 1/2 way through the run. However she then went on at about 14 months of training to mark a 144. However that is not at all the norm.
As for needing to have the horse going in a curb and one handed in free style. That is really not true. Free Style reining is the one time you can 2 hand your horse even in a curb. That being said. You still have to be very solid on all your maneuvers. A month of training is not even close to enough to even think about showing a reiner.
Nrhareiner, I was waiting for you to show up. When I came into this forum you are the one who opened my eyes that reining is not for the faint of heart and takes a lot of time, dedication, skill, training, etc. I wonder where the OP went...she had posted in another thread that this horse was already doing "flying spins"