You should wear comfortable and loose pants or a skirt both to the appointment and probably for the rest of the day afterwards. You will likely be sore after the waxing, so a pair of tight pants would be a bad idea for this appointment.

Avoid heavy exercise for at least 24 hours after waxing. Avoid saunas, steam rooms, whirlpools and other heated sources for at least 48 hours. Do not use exfoliating products (AHAs, scrubs, etc) and loofas for at least 24 hours after waxing as they might further irritate your skin

Exfoliate the treatment area to remove all dead skin that may hamper treatment. Ensure your hair is at least the length of a grain of rice. Avoid hot tubs, saunas, and tanning beds. Avoid direct sunlight and any sun damage.