I am not able to see my questions and answeres . how to ?

I would answer, but you still wouldn't be able to see it.

Click on your Username on the Left side of the page on the Next page you should be able to see a List of your Questions and your Answers for Questions go to the My Questions Tab for the Answers go to the My Answers Tab

Click on your avatar to see your questions and answers, and points and level on the next page.

Sure you are. You can go here /activity/questions or you can click on your username in the upper left of your screen, just below the link for Notifications. Either of those will take you straight to your YA Activity, and the default is to show you your "My Questions" list first. You can then click "My Answers" to view all the answers you've posted, that are still standing.

Go here to see your stuff: /activity/questions

Answer another users question and then click on your username.

Or click on your Yahoo Answers username on the left left of the website.