Diapers, Slings and all things baby. Need advice!

Im

My youngest is 9 and I am totally out of the baby loop. Whats the best baby gear out there? I used to buy Pampers, are there any others out there better? Costco, Target. What about slings? Are those worth buying and if so what's a good one? Anything else you can think of that I need to know thanks. This is most likely my last baby so I don't want to buy a ton of stuff just what's most helpful. Thanks!!!