Nothing beats experience behind the wheel or can replace it. I am sure that when you started pulling your 5th wheel you were concerned about overhead clearance and turning clearances. These same concerns are there with a Class A but you gradually get used to it.
Many people have used a piece of tape, or mark on the windshield that aligns with the left hand side of the coach. In other words, when you sit normally in the driver's seat, and you align the tape/mark on the windshield with a location on the road ahead, the left side of the coach will pass over that mark.
After you feel comfortable in the driver's seat, this will all become second nature and you will realize the advantages to having that huge windshield and your elevated sitting position as you scan the highway and traffic.