There is no standard for how long the supply line is, and what wax ring you may need will depend on where your flange is actually installed. They are designed to be installed on TOP of the FINISHED flooring, but that does not happen all that much...often, it's deeper in the floor. Also, it's a good idea to replace the shutoff valve at the wall to be on the safe side. Those choices will depend on what kind of pipe you have, and whether the valve is soldered on, a compression fitting, or a slide-on type. You may want to replace the anchor bolts, but if the existing ones are brass or stainless steel, they MAY be worthwhile keeping...there's no standard on how thick the bottom of the toilet is, so they could be too short. If too long, you can cut them down if needed, but can't make them longer! On the supply hose, it can be a little long, and if a bit more, you can loop it, but you don't want it to be tight and under tension once installed.
Terry likes to use brass ones in a set that has two sets of nuts and washers for each bolt...then, he uses the first set to anchor the bolts to the flange, and the second ones to anchor the toilet. That keeps them upright and not bending over while trying to install the toilet.
Code calls for sealing the toilet around the front 3/4'ers of the toilet to make it more sanitary (i.e., prevent dribbles, mop water, etc., from getting underneath where it's hard to clean). You don't want to use silicone caulk for that, but one that's easier to remove when the time comes.
Without at least some pictures and additional info, can't say for sure.