I recommend looking at lucieslist - they have a great list to get you started and then articles on each section Incase you want to dive deeper. Amazon has the best perks of all online registries and you can add items from any website. You get a huge welcome box (5x better than target and buy buy baby’s) and you get a 10-15% discount on anything that people don’t buy. Add everything you intend to buy to get the discount. Easy returns too so decisions aren’t permanent. I know it’s overwhelming but it’s infinitely more fun when you realize you’re picking out things your little baby will use!
Honestly, it'll really depend on whether you have high maintenance or low maintenance tendencies. There's a lot that people say is a must have that I personally found unnecessary and a waste of money. The best advice I got was keep things to a minimum, you'll be fine without a lit of stuff, and get things you feel are lacking as you decide you need them. Definitely worth having are postpartum care supplies for yourself, depending on how you plan to deliver; I highly recommend a My Brest Friend breastfeeding pillow too. It saves me a looot of back pain. Super comfy to feed my daughter using that thing, if you're planning on breastfeeding. Obviously you're going to need a place for baby to sleep, and looooots of swaddles or receiving blankets whatever. It's a good idea to get like 5+ footie sleepers for babies born during the winter unless you live in a hot place... Um... Yeah and definitely put together an infant first aid kit! Hopefully you won't need to use it but you're always better off having one!