Providing these water heater things are fine there is the chance that the cord running to the disposal has developed a short or a wire has become disconnected. You will need to disassemble the unit to verify all wires remain securely fastened. The last conclusion is that the motor has burned out, in which case you will need to replace the disposal unit.
The wax ring is used to seal the drain outlet on the bottom of the toilet to the drain opening in the floor. When a toilet is installed, the ring is placed onto the drain... the toilet is dropped onto the ring... and the toilet bolts (also known as closet bolts) are tightened enough to lock the toilet in place. If that wax gasket ring starts to fail or isn't seated properly? Sewer gasses can sneak out from under your toilet causing your bathroom to have that suspicious smell. It can also cause water line repair to escape, sometimes invisibly, with each flush potentially damaging the floor hidden under the toilet.
If you bought the same unit it should line right up, if you were unable, you will need to remove or add length to the existing piping. This may require you to splice together copper with plastic, don't let this scare you the hardware store will have all of the necessary parts.
Clean the hole in the gutter railing first. It must be free of any debris, so you may want to clean the entire drain channel using a proper cleaner. In this way, you will have a clean surface area which will allow you to repair the hole more easily.
As with anything, when you are not sure how to fix a plumbing issue and when you don't have the proper equipment, you should contact a professional. They can usually find out what the problem is and resolve it for you in a short period of time. They will also be able to tell you if you have any other problems and water line repair they can suggest resolutions.
Turn the water off at the main shutoff valve at the street. You should be able to take a pair of pliers(or your bare hands) and turn the valve at the water meter to shut off the water to your home. Once you have shut off the water you can cut the pipe around the leak and make the repair.
Then, you can take your new shower parts home and reinstall them in the inner assembly. It is very important that everything be aligned properly and tightened to prevent leaks. Beware of over tightening, however, since this can also cause problems. Once you are sure everything is installed properly, replace the cover plate and turn the water back on to test your repair work. With a little bit of work, your do-it-yourself shower repair project can be a success. It does not take an expert, just a little effort and know how.