I like to recommend this site as a quick reference guide to find exercises if I want to change things up when planning for a workout. There is a directory sorted by muscle group and articles that are actually fairly well written, including citations usually if that interests you. I linked to the general article because it links to the more specific muscle groups from it because like most exercise focused sites it can be a little tough to navigate.
As another user noted, deadlifts when done with good form will work your traps and spinal erectors along with the rest of the posterior chain. Take some time to really make sure you have good form before you hurt yourself when you try to push higher weights.
I strongly recommend following a more strict workout in the beginning rather than winging it so that you don't start yourself off with major muscle imbalances. At the very least, add in some bicep work on your back day, triceps on your chest day, and abs and shoulders whenever you can squeeze them in.
Ideally you would use a freestanding barbell, but a dumbbell modification is perfectly okay. You'll lose out on working a lot of your stabilizers and will likely have to favor your back or legs with positioning at a smith machine and it makes the overall movement of the exercise pretty awkward and ineffective.