Minimal pain. Sometimes there is some residual pain while you are healing from the infection. This should happen rather quickly. If you continue to have a significant amount of pain then you should call you dentist and have this evaluated.
Should improve soon. The gum pain may be from the special clamp used to hold the rubber dam in place to keep the tooth isolated from bacteria and you protected from the cleaning solutions. May also be from the anesthesitic injection, or from the infection. You should improve soon. Ibuprofen 400 - 600 mg 4x/day for 2 - 3 days will help if it is from inflammation of the ligament that the tooth root sits in.