I have a feeling we have similar hair types, I attached a pic of mine for reference. Shampoo and conditioner doesn’t need to be high end, just something that gives you hella moisture without being heavy. I use the black elvive shampoo and conditioner. I also use suave leave in repair treatment after I shower and when my hair is dry sometimes
I think what will help you figure out your curl pattern is to just start with brushing/combing it out while it’s wet, and scrunching it with a t shirt until it air dries. Don’t worry about diffusing right now because it’s difficult imo, especially when you don’t know your pattern yet. Then you can kinda go from there