Hey there Sohel,
First of all, Welcome to what is a beautiful hobby

The Ft Racer is not really a plane for beginners. You should have gone for a much simpler airframe in my opinion.
However, even the FT Racer being so docile shouldn't roll to the right and crash....
So let's check a few things, shall we?
1) Are you using a Motor from a Quad? Since what we normally see is that the motor rotation is CCW if the plane is viewed from the front. I.e nose on view. The motor should be turning CW as seen from the cockpit.
2) It could also be the case of a Normal RC plane motor but with two wires reversed.
3) you could have also put the propeller on Backwards. Easiest way to check is if the numbers on the prop are facing the front or not.
4) The thrust line may not be Okay.
5) Maybe your Ailerons are Reversed?
Please get back with your motor specs, prop specs and a photo of the front of the plane. And if possible, a video
Regards,
Prabal