My hardwood floor is already finished without applying glue on groove and tongue and nailed face to subfloor on the last row by handyman . I don't know what will happen later so i am worring it is going on bad.Thank you for advice !

Hardwood flooring has been installed without glue for a long time. Top-nailing the last couple of rows is acceptable and has been done since flooring has been installed over a sub-floor.

Thankyou

Why hire a handyman jack of all trades instead of a seasoned hardwood person?

It happens SP. I had a customer in NY, NY a few months and asked who's installing the floor. "Oh, just some guy I found off the street" Most folks very new to the concept of hardwood flooring (but unaware of the pitfalls) think anyone can do it.