Word of warning about gearing.
Always check the heat of the motor after 2 minutes too after you change your gearing.
As you are new into r/c, it would be costly and disheartening to ruin a motor - it is for anyone!
It is good that you are asking questions though, as there are plenty of them... 15 years of racing and I still find many of them to ask
Sounds like the gearing has already been covered, once you have worked out what gear ratio you need and if your budget allows, buy pinion gears one tooth bigger and smaller each side of your preferred ratio for a bit of flexability/tuning.