I was in your shoes just over a year ago when I started.
Since you just started I would stick with testing ammonia, nitrites, and nitrates at first. This will tell you when the cycle is complete. Get the cheapest kits you can find for ammonia and nitrites. Nitrates are more important but you want it when cycling. Then you want to watch the other levels like Alk, Ca, PO4, and nitrates. I check Mg once every few weeks.
I would start off with Salifert kits as well because they are cheaper and still accurate. The components are nicer on the Red Sea but I have trouble seeing the slight changes in all the color kits. So I rely heavily on my Hanna Alk and P04 testers. They are more expensive but I test my alk every 3 days or so and it is fast with the hanna. I use red sea for Ca, Mg, and Nitrates simply because it was the first kit I bought and I just keep buying refills.
Make sure you watch the expire dates on any liquid test kits you buy. Most I buy online expire in over a year but on store shelves they might sit. Oh and I have had ZERO luck using the hanna Calcium tester so cannot recommend that to anyone.