For when the baby is born, you actually don’t need a lot. You need some vests, sleepsuits. I would get a couple of different style of sleepsuits from different places, you’ll quickly work out what suits your baby. I would get no more than two swaddle blankets/cellular blankets and two sleep bags because your baby will probably only like one - DD hated being swaddled and pulls blankets over her head so she got put in sleep bags straight away but some babies hate sleep bags. Love to dream are good sleep bags for newborns because you can have swaddle options. However, they are expensive. You need more muslins than you could ever imagine. When you think you have enough, buy at least another 15. You want some large ones as well as the regular size muslins. Also get yourself a travel mug with a closable lid, a water bottle and a shoulder bag - you’ll be taking drinks, snacks, your phone, maybe a charger, possibly a bottle or a dummy, maybe some laundry up and down stairs with a baby. You might want a shawl for your shoulders, breast or formula feeding it can get cold doing the night feeds.
Some babies like the Moses basket/bedside crib and some don’t. Some like slings, some don’t. If you think your baby would like a sling or a chair or you’ve realised you need a jacket or a cardigan, you can pretty much get something delivered the next day. We didn’t have a baby bath until a few days in, when we realised we ordered one at 2am and it was click and collect at 3pm that afternoon. So don’t worry about having everything straight away, you can buy things as you learn about your baby and what might work for them.
If you formula feed, I would recommend MAM bottles and a perfect prep machine. You’ll probably want a night light for the night feeds. We have the shnuggle light, it works well for us but it wouldn’t be bright enough for me to see what I was doing to get a baby to latch and it’s not bright enough for a nappy change. We have the groegg but honestly we don’t use it, you can tell if a room is too hot or cold by being in it but you’ll also find that many other things have a room thermometer (we have a bath thermometer that does the room too, the baby monitor has a thermometer, the charging stand for the shnuggle light has one). We found that having the thermostat in the room where the baby was sleeping helped because we set the temperature to kick in at 18c, if it’s colder than she wakes a lot.
Get some cook meals, new parents get 10% discount. Buy some and put them in your freezer. I didn’t have the energy towards the end of my pregnancy to batch cook but the cook meals means you can have a proper meal without actually thinking about it.