recently, I completed 2 buyer orders. form my new gig.
The buyer is happy with me. Inbox, she thanked me.
And said give me more work.
But he doesn’t give me any review.
Now what ranking will have any effect on my gig for this
I can ask him for a review
Never ask her a review it will create a big bad impact for your profile. It’s normal that some of your buyer will complete your order without any rating. But now worries you will get a auto 5 
review after a certain period.
thank you for the correctly information
simply wait brother … don’t worry
and remember don’t aks him for your review. it breaks the rule Fiverr’s Terms of Service
Don’t ask any buyer to give you a review. It will be count as a bad effect for your gig.