Most older coaches are probably going to be in the area of 96" width, length usually about 35'. Newer coaches, 102" wide x 40 - 45', depends on what the owners wanted. As far as the Ohio Turnpike, nothing on here about restrictions, as long as you meet the Federal Govt's length and weight restrictions.
Ohio Turnpike Commission - Home Page
Driving a large vehicle takes a little getting used too, main thing as far as I'm concerned is to make sure your mirrors are properly adjusted, practice at a large empty parking lot until you are comfortable with knowing your sight lines. There are RV driving courses available, you can do a google search for them, also, might contact a local trucking school, many of them will offer a short course for a fee on RV driving, backing and turning.