Is there anything I can do about blister in my mouth?

Blister in mouth. The good news is that unless the blister is in a location where you often accidently bite it, it will heal in a few days. A topical over the counter anesthetic gel can be helpful to soothe pain and discomfort. Avoid food and drink that are temperature extremes, as well as those that are salty or spicy as they can be irritating to the blistered area. If you have blisters often, see your dentist.
Comfort strategies. Usually the best remedies are palliative (for comfort): orabase (an ointment with a topical anesthetic), warm salt water rinses, and perhaps "magic mouthwash" which is mylanta mixed with a topical anesthetic such as Lidocaine or benzocaine.