Waivers and the law etc
Just one thing, ignore all the waiver will not stand up they can sue you for anything talk this is not the US, and these are not lawyers.
Start with the lawyer and find out what your liability is
Have a copy of your waiver, do some research 1st on this
Write down all the required safety rules
A copy the safety briefing you will give.
And a clear description of the sport for the lawyer.
The rules are different from to province to province, as far as liability goes but generally you have to be negligent or create a unsafe environment. But once again I am not a lawyer so get some legal advice.
Beyond that treat and plan it as a business, our field here in BC has 12 rentals and they are often all rented out a week in advance of a game.