CT, welcome to the site! I love 29s and the kit you bought is what I started back into the hobby with 3+ years ago after being out of it for almost 30yrs. The Top Fin 30 hang-on-back isn't the best filter in terms of bio media. All they rely on is that thin black sponge for bio media.
Just as an example, but on my 29, I run a AquaClear 30 HOB and a two cheap eBay sponge bubbler filters.
IMO, the only water parameters you should be concerned with at this point is seeing nothing but nitrates. Until that happens, pH, GH and KH are meaningless. You need an API master test kit for this. Test strips are for Petco and Petsmart. LOL..
You have a lot of cool stocking options for a 29g. You could go as simple as two fancy goldfish, which are a lot more fun than people give them credit for, or you could go with a vast array of smaller tropicals. In the 29 in my sig, I haven and angel as a center piece fish, 6 julii corys, 6 silver hatchets and 5 celestial pearl danios. It's a very active tank. I've got lots of java fern and anubias nana in this tank with a basic T8 fluorescent hood/light.