Um, if you don’t have an electric mixer, then you have no choice but to use a whisk. I have no clue how many “strokes” to use. Your batter has to be smooth and free of lumps. So when that happens, you know your batter is ready.
I don’t think you should even attempt decorating a cake until you have mastered making a simple cake especially since you don’t have all the basic equipment.
Stick to Duncan Hines cakes for now. They are quite solid and springy so good cakes to practice on.
A cooling rack is not the stove-top burner. 
Cooling rack is a seperate accessory … basically just a rack you can place anywhere.
I don’t have any experience with the other types of pans you mentioned so I cannot advise you. Perhaps someone else can.
