Your sizes are different thatn we have here but for the first few weeks DS lived in newborn sleepers. I never even tried to put cute outfits on him (way to hard) I just got a few cute sleepers. He grew fast but he also spit up a lot and had a lot of diaper leaks so we needed quite a few so we didn;t have to do laundry every day.

Things we could not have lived without in the early days:
- Burp rags - DS was great at spitting up and even though I had 20 of them it never felt like I had enough
- Bouncy Chair - this was a godsend
- Baby swing - when DS wwas 2month the swing allowed me to have showers or get dinner cooked
- Car seat cover - it was winter when DS was born and the car seat cover allowed me to dress him him his sleepers but ensure he was always warm and covered

We had a baby tub but we only used it for about 6 weeks, then we just laid him down in the big tub with a small amount of water. When DS learned to stand we started using the tub again as it made it harder to stand, but after a few weeks he could climb out of that as well so we got a bath ring seat.