Don’t assume that you’re missing something if you have a question that cannot be answered within the guidelines of the shed plans. Builders at all levels will always have questions and it is better to ask the question than miss something important in the process. Go online and find a forum or a video if you have a question. Better yet, read all the little print that you skipped over in your shed plan and see if the answer is there, it might be.
I don't waste my time on free plans, store-bought sheds, or ready-made, mail order kit solutions... been there, done that. Free means lack of user feedback and you get absolutely no customer support. With store-bought and ready-made mail order sheds: they're flimsy, profit-driven solutions that I've always had to tear apart and modify too much to get the storage space to work or to match the character and style of the home.