Since you're just starting out, there's a lot to take in- fortunately this part is pretty straight forward and you've been given great advice above. If you're the type of person that likes to tinker and put your own twist on things to try and make it kind of your own, I'd prepare the whole gallon of meat the same way. I prefer ground meat over cubed because you can get a quicker, more thorough mix of everything, also, it'll smear in sets where you want it smeared where a chunk will just sit there. Ideally, if you have a critter checking out your dirt hole and it's close enough to take a chunk of bait from a hole, you should have already caught it, but as trappers we know things don't often go as planned- that's another reason I like ground bait, it can be harder for the critter to get it out of a hole which should get you more foot action at a set and increase chances of picking that critter up that came in and may have avoided the pan on initial approach.
There are a whole lot of ingredients you can add to give your concoction a slightly different odor profile, just remember that ingredients need time to be thoroughly incorporated to a formulation, so don't keep adding until YOUR nose is happy.... Canines, etc can smell the slightest amount of ingredients you add. You can find all sorts of info on ingredients either here in the archives or in the many books published on bait and lure making. Best of Luck!!!