Every person's essentials will be different and you may find you buy things you don't like/end up using and other things you can't be without. I think I was fairly minimal with DC1 so here are my suggestions:
Next-to-me cot/moses basket for first 6 months when they're in your room
Sheets and waterproof mattress protector for the next-to-me
Swaddling blankets if you want to swaddle (I gave up with these after 4 weeks because DC kicked her way out of them!)
Sleeping bags (life saver at night for helping DC feel secure)
Clothes - sleepsuits, vests, leggings, body suits (I'd go for comfy things for the first few months and perhaps have a couple of nicer outfits for photos or occasions. You won't want to be wrestling them into tights/fussy clothes on a daily basis)
Mittens/hats/socks
Cellular blanket
Muslins/bibs (all the muslins because they're really handy for everything)
Tommee Tippee perfect prep machine/bottles/formula (IF you are going to formula feed. I did and the perfect prep was a game changer. People will disagree but it worked for us)
Steriliser for bottles if using
If breastfeeding, a pump, milk storage bags, nipple shields, nipple cream, etc
Sudocrem/baby bath/shampoo/moisturiser/etc
Thermometer (we have one that can go in the bath and in their room but also one for baby to check their temperature)
You can get a kit from Tommee Tippee which includes all the essentials like a brush, toothbrush, comb, nail clippers which is really handy
Nosefrieda(?) nasal suction thing, which is a bit gross but makes clearing snot a lot less distressing
Nappy bin and refills for the bin (not essential but useful)
Baby bath/bath support
Pram and car seat
Sling/wrap (not essential but nice to have)
Nappy bag
Nappies/wipes/nappy bags
Dummy (if you want to use one)
Have some things in your medicine cabinet in advance that are suitable for newborns, like gas drops, colic relief drops and nasal spray/drops - so much easier if you've got things in just in case instead of having to run out and find them last minute
Toys aren't essential for a newborn but you might like to look at high contrast books/cards which are good for newborns to look at/teddies/Lamaze toys that jingle or have different textures
Bouncer/rocker chair (even if just for somewhere to put baby down safely for a few minutes)
Floor mat for tummy time (or a blanket is fine)
Towels/flannels/wash cloths
Toiletries like cotton wool/ear buds just in case you need them
You may want to get nursery furniture, so cot (for when they're bigger), changing table, glider/rocking chair and wardrobe/drawers for storage.
Changing mat
White noise machine (or there are playlists on Youtube you could put on your phone)
Week by week cards if you want to take weekly photos (not essential but nice)
I'm sure there's things I've forgotten but this might be a good starting point.