Your question was answered well and I second getting the credit card and the plus membership. You will be surprised at what you receive.
I have never applied online. I applied in person. Get the credit card so you can get some sorta perk as well
When you walk in go straight ahead to member services desk and those nice people will get you set up in just a few minutes. Go with the plus membership as it gives you some awesome benefits. Like cash back (sam's cash) on all your purchases and early shopping hours.
Online. Or apply in person at help desk.
Thanks! Your answer is awaiting moderation.