DS is 4 months old. Here are our must haves:
Next2me or similar for sleeping
Portable changing mat and a decent rucksack, no need for a specific baby bag.
Decent sling - we have the ergo adapt and love it. We didn't use a pram for the first 3 months just carried DS everywhere.
Cheeky wipes, washable nappies (we have bambino miosolos) and a cheap nappy bin
Snuggle bath - it's brilliant
Something to put them into or on in each room - we have a bumbo, a bouncy chair thing, a baby gym mat and keep the pram in the kitchen. Although you can get all this when baby is bigger, for now just a sling is fine and allows the baby to nap while you can potter about if you fancy it. We got all of these things 2nd hand - are are super cheap on facebook marketplace.
Clothes wise dont go too crazy. DS is on the 95th percentile and has outgrown newborn, 0-3, 3-6, 6-9 in 4 months! We got all our clothes handed down from family thank goodness because otherwise would have cost a fortune to keep buying new clothes in bigger sizes every few weeks.
You will get lots of 3-6 as presents but hardly any 6-9.
Lots of Muslims and dribble bibs, also sockons are great if your baby is wearing outfits that need socks.
We haven't needed any toys as such yet also hes starting to show a little interest in one that has a crinkle noise.
For you - decent breastpads (washable are nicer and less faff) comfy clothes that are easy to feed in (if bf'ing) or pjs. Have 2 dressing gowns so one 2cm be in the wash if you get puked on.
Congratulations!