It should take several hours on the ground (self and dual study) and 3-5 hours in the air - to do it properly.
One the ground you'll want to have a full understanding of the systems - eg how does a V/P prop work mechanically, how to operate it and what might go wrong with it. Same for the retractable landing gear. I'd expect that you would learn about these systems generally and also concentrate on the specifics of the Arrow (the Arrow's gear system is pretty standard).
In the air, you'd get comfortable with the plane, learn how to operate and manage all of the systems and also cover what to do if things go wrong (eg emergency gear extensions).
There is a saying about gear up landings - "there are those that have and those that will" (it has probably been coined by those that have...)
No matter what aircraft I happen to be flying, I always check again on short final that the gear is down.
Also, on the Arrow, there are 2 sets of lights controlled by roller switches on either side of the main switch bar - I forget which one does this but if you turn one set of lights on, it assumes you are flying at night and dims the landing gear lights to the extent that you cannot see them during the day - in other words, if you lower the gear, feel the extra drag but see no green lights, check that switch!!
The Arrow is a great plane - I did my initial "complex" training in a 1967 model and had many happy hours flying it thereafter.