What tools are necessary for brake pads/sparkplugs

Look at the pads and rotors to see how much brake pad lining is left. Check the brake discs to see if there's any issues with excess corrosion. It's common to see just a little unevenness in the disk/pad contact area. This is not an issue, unless it's excessive.

Unless you're super heavy on the brake pedal, or there's an excessive amount of corrosion, the brakes probably won't need to be done (or somehow Texas grew mountains I'm not aware of).

For tools, I'd say the next thing to look at is a torque wrench or two. Inexpensive is fine - set the torque on the handle and listen for a click works fine if you're not going to be working on cars for a living. (Harbor freight's got a 10-150 ft lb for $22, which won't quite go up to the axle nut torque, but it'll do a lot of things. They've got a few 1/2" drive ones that will get you further, but the low end doesn't work for about 95% of what you'll need to do.)

At 120,000 miles, I would be looking at cleaning out the EGR instead. It's about time to change out the engine coolant, which makes it much easier to pull all the EGR hoses. Get a couple extra gaskets and clean out the intake manifold and throttle body while you're at it.

With parts, for the most part, keep to the originals.

 

I think you can get by with 10mm and 14mm sockets for all of this, and a 14mm specialty spark plug socket of course, and an extension long enough to reach the plug. You can use the car's lug wrench to get the wheels off, but a 21mm socket and torque wrench accurate at the 76 ft lb lug torque would be better.

Torque wrenches that will be accurate for the spec'd torque of the spark plugs and of the caliper pin bolts are good.

Brakes, I like to go in frequently and just inspect, not necessarily change anything. So, a (measuring) caliper, or micrometer, to measure the pads and rotors that you've got. If the car's been well taken care of, you may find you are nowhere near needing pads yet.

If you write down the thicknesses you found, and the mileage, and then the next time you inspect you write down those thicknesses and mileage, those two points will let you draw a line out to where you'll expect to need new pads. (Keep inspecting, of course, because there could always be a problem that crops up, or a change in your driving habits, making things wear faster than you first project. Each time you inspect, you get another point you can use to fit your projection line.)