About5-6inches up my vagina it becomes very painful like something is about to tear? What is it? Is this what all women experience during first time?

Not sure. Have a pelvic exam done by your physician. They should be able to help find the cause.
Dr. can evaluate. It is difficult to know what is causing the pain without a good physical examination. A gynecologist would be able to do an internal exam to determine the possible cause. It is not normal to have pain inside the vagina after sex, and this should be evaluated for a possible infection or a laceration within the vagina.
Not sure. Get an pelvic exam . Your doctor should be then able to answer your question.