Hi Ali,
Both sentences in English are in the present tense and make sense. There are some differences, however.
My nose itches - this is in the simple present tense. It is used to describe habits, unchanging situations, general truths, and fixed arrangements.
My nose is itching - this is in the present progressive. This means that the action is going on in the moment.
So if you say: my nose itches, you would be saying generally that your nose is itchy. If you say my nose is itching, that would mean that at that very moment your nose is itching.
I hope this helps!