What is the minimum number of hair removal sessions required?

I have an inquiry regarding underarm laser hair removal.

I had hair removal done once before, but it wasn't permanent, so I usually shave. However, recently, my skin has been severely irritated, and I have developed redness and discoloration, so I have started considering laser hair removal.

I would like to know how many treatment sessions are usually required to see satisfactory results, and also how often the treatments are spaced out.

I would also like to inquire about the level of pain, the duration of the procedure, and whether I can resume daily activities such as showering or exercising immediately afterward. As my skin is sensitive, please inform me of any potential side effects or precautions I should take after hair removal. Finally, please check the cost, the status of current promotions, and the earliest available appointment date. Thank you.