Hey there Terri, and welcome to planDisney!
I love that you have asked this question, and I am honored to be the one to give my perspective. I always recommend not starting with too many days, especially if it is your first visit. I think 3 to 4 nights is just the right amount of days to get your feet wet and experience some (not all) of the magic to avoid being overwhelmed. With those 3 or 4 nights, plan to visit two theme parks you have on the top of your list and save the others for another visit. When you are not visiting the theme parks, those days can be used to enjoy your resort and its amenities or take a day to do some shopping and enjoy a meal at
Disney Springs. Regarding the day of the week to start a vacation, that is totally up to you and your schedule. Having said that, I am partial to Monday and Tuesday start dates, though there is no specific reason I prefer those days.
Please return should you have additional questions; we would love to help you in the planning phase of a potential
Walt Disney World Resort vacation!
Have a magical experience!
Raquel