The usual way is to have 2 or 3 degrees of right thrust. You would be correct in presuming that the front end of the crank would be slightly to the right of the aft end when you are sitting in the plane. I do hope that you are extremely small in stature if you intend to try sitting in the plane.

A lot of the new ARFs' have a unique motor mount that builds in the thrust angle when you mount the engine. If your mount comes in two halves, check to see if changing the mounts to the opposite sides of the engine will change your thrust angle to right thrust.

If not, install your engine at the angle the firewall is currently at. When you take it out for the first time, do several taxi tests prior to flying it. If the plane wnats to severely turn left at medium taxi speeds, install a washer or two under the left motor mount legs, between the motor mount and the firewall, to acheive right thrust.

The condition you have is not that big a deal to correct. Just remember to take (4) number 4 or 6 washers to the field with you on the first day of flight.