Hi Kranthi,
You need to assign your user proper authorizations. Please see section Section 3.4 and 3.5 of Personas Configuration Guide to create Personas role and how to assign them. For a start, you can assign "-1" which will give full editing rights for your user.
Again, it is quiet important that you check 3.1.3, 3.1.4 and 3.3 to make sure your settings are correct.
Hope it helps!!
Regards,
Sushant