A disclaimer - I am not a doctor, but have lived with moderate scoliosis since the age of 13, and now my daughter has it as well.
To answer some questions, it often appears in teens (more prevalent in girls), can be inherited, but the exact causes are unknown, hence the term ‘idiopathic’.
In general, it can’t be reversed considerably, unless you have surgery, which is recommended in severe cases – these are usually picked up by doctors quite quickly, so not your case, please don’t worry.
Mild scoliosis is super common, but it is not diagnosed often and doesn’t affect the quality of life. Moderate scoliosis can cause back pain at some point, as the muscles around the curve start to compensate for the imbalance by either shortening (stiffening) on one side and lengthening on the other. This can be exacerbated by carrying heavy backpacks or bags on one shoulder only (my endless fight with my DD).
Getting into yoga or Pilates is a good way to build body awareness, so you learn to compensate for the curve. Otherwise, stretching arms up towards the ceiling daily to lengthen the spine is also good. Special exercises work only if you do them regularly (good luck with teens with that).