I can't see any ulcers or lump inside my mouth but different parts of my tongue is paining occasionally and there are small white painless spots ?

Needs to be seen: We can give you a list of 100 possibilities which would be merely educated guesses or you can see your own dentist who can give you an accurate answer. I suggest the second solution.

Geographic tongue: also called benign migratory glossitis. It is a benign condition characterized by inflammation of the tongue and it usually heals without treatment. See your dentist for evaluation, if concerned.