If it looks like white circles then it is possibly "Geographic Tongue". You don't have to worry about them. It will move and change pattern, therefore, they are called "geographic".

The reason for geographic tongue occurrence is not known. Some studies show that it is occurred because of strain. Sometimes, the patient feels like burning but no treatment is suggested accept for antiseptic gargles.

 You can also try live culture yogurt to help level out the bacteria levels in your mouth.