Can I expect skin tone improvement after the blemish treatment?

Hello. My skin tone is uneven overall, and noticeable pigmentation in certain spots is making me consider consulting a clinic. The blemishes stand out even more when I am not wearing makeup, so I am looking into methods to address the pigmentation itself rather than simply brightening my skin tone. I would like to know how clinics typically assess my skin condition before determining the treatment method for blemishes. I would also like to know if I can expect some improvement after just one or two sessions, or if I need multiple treatments at regular intervals. Additionally, I am curious if my skin might become sensitive or if the color could temporarily darken after treatment. Please also let me know what specific areas you focus on during the actual consultation.