Are you going to be having a baby shower?
I would get a couple boxes..that's it. My daughter is 10 months old, weighs 20 pounds and is in size 3. She was 6 pounds, 13 oz at birth. I put her in nb for a couple weeks but switched to size 1. They weren't super snug but they did the job. I started buying clothes at 9 weeks lol. I don't think it's too early to buy the basics.
If you buy too many it shouldn't be a problem. Most stores, especially walmart, will let you exchange unopened packs for a larger size.
You don't want to buy too many of one specific brand because you don't know what your baby will like, same thing with pacifiers, and bottles. I would definitely wait until you have your shower and then go from there.
I honestly waited to buy pampers and wipes because I knew I was having a baby shower. I received over 20,000 wipes and boxes and boxes of diapers. So I'm good on those for the next 7 months.
If you're going to buy clothes make sure you get them in different sizes, we have more 0-3 months clothes than I know what to do with, he hasn't worn half of them
The stores in my state will exchange unopened packages. I've already made sure that I'm using the big boxes last so I can get a bigger size if I need to
Be careful some babies do have allergies.
Huggies worked best for me and if your having a baby shower dont buy a bunch because you will get lots of diapers