Is it possible to get free review for a new seller without selling any gig?
No, it is not possible. You can only get a review by actually selling something.
Also, it is against Fiverr’s Terms of Service to offer academic writing.
I suggest you read the Terms of Service and the Community Standards here before you start selling:
The Seller Help Center will also help you answer any other questions: https://sellers.fiverr.com/en
oops. So my gig is against the community?
Yes, that is what I just told you. Three of your gigs are violating the Terms of Service. I suggest you familiarize yourself with the links I sent you and delete the three academic writing gigs as soon as possible.