Getting my feet in the water

So I got a 20 gallon long aquarium with a stand, and all the stuff I need to start working on the cycle on an Amazon order list. I wanted to make it a planted aquarium, in sand, no tabs, so I was gonna go with plants that get their nutrients from the water. Planning on getting some plant supplements. First thing, I do most of my research on Ai, 2 months ago I knew nothing. So I’d appreciate any suggestions on what I’m doing right or wrong. I want to house a betta fish, and shrimp of some kind, I want Cherry shrimp, but Ai pointed me towards Amano Shrimp, but after some YouTube videos, it was clear why. I’d rather just pop in a couple Nerite snails.

Also, is a 3 to 1 part water to peroxide solution soak, the best way to clean plants I bring home? Trust me I got a ton of info, that I shouldn’t break down to people who already know. I’m trying to get clarity, and confidence in what I’m doing. Going based off purely what a robot says can be a bit confusing, there’s so many new words, when I try to talk about the process of buying a used sponge from a pet store, I can tell it tickles my family’s brain, but the part that kinda confuses me, is when do I add the ammonia? After I soak my sponges in the gunk, and pour the remaining over my filter, or before? The ammonia is food right? So I add it after?

Oh this is the thing I’m going to ask, that no one might be able to answer. How do I use the API freshwater test kit? Those tubes take a specific amount of my tank water, and then drop or drops of some chemicals, and then I compare colors to a chart?