If you begin a sentence with is it followed comma?

No, you don't need a comma after "is it" at the beginning of a sentence.

For example:

* Is it raining outside?

* Is it possible to learn a new language in a month?

The only time you would use a comma after "is it" is if it's part of a longer introductory phrase or clause that needs to be set off from the rest of the sentence. For example:

* Is it, in your opinion, a good idea to invest in the stock market?

* Is it, considering the current circumstances, still safe to travel?