My baby is 11 weeks old, so this is all fairly fresh for me - and my expertise therefore extends only to 11 weeks as well…
I breastfed like a champ in hospital, but had awful problems once my milk came in, when I got terribly engorgement which stretched my nipples out so tight she couldn’t latch on. The only thing that worked for me was these Aventnipple shields, recommended by my lactation consultant. I know there is a lot of advice against using them, but for me they were the difference between breastfeeding and not breastfeeding. I used them for about 4 weeks and finally weaned myself off them - and now it’s a very easy thing to feed her. It hurts like holy hell to start with - but perservere, it soon stops, and now almost feels pleasant.
Other things that were great - Avent 0-3mo pacifiers - she had a bad habit of staying latched on for an hour or so after finishing eating for some feeds simply enjoying the comfort, and this achieved the same thing. Even now, it can just be the tipping point to get her to sleep if she’s very tired. She very much rejects it when she doesn’t want it, but great for settling. You may need to try different brands - she loves Avent, but hates Nuk, even though to my eye they are pretty much identical.
Large wraps - I’m using 120cm square muslin ones as it’s summer here, but they come in cotton and flannelette too. Great to help them sleep, and I use them as sunshades for her pram and for covering the floor for tummy time.
I cloth nappy her, so can’t advise much about nappies etc, but if you are interested in going that route, BumGenius 3.0 are great - have fit her from a couple of weeks old (and she was a small 3kg baby when born). As easy to put on as disposables, very cute, and costwise will save us several grand, as they can last her to toilet training (and for any other kids that follow).
Accordingly, we use Badger Baby Balm ointment for her bum, as you can’t use zinc products on cloth nappies - and it’s fantastic stuff. Clears up any hint of a rash within a day or so, and good at prevention (when Mum is diligent about using it that is!).
Other things we use regularly:
Slings (one I made myself following this pattern), and an Ergo. Both are the best at settling her (she’ll sleep for 4 hours during the day wandering around the shops etc, and they keep her weight on your hips, which is better for your back. Many people start with a Baby Bjorn, but give up when it gets too much weight - the Ergo etc don’t have this problem.
Playgym - we have a cool wooden one from Ikea, and she’s enjoyed this from far earlier than I ever thought - 6 weeks or so.
We don’t have a separate change table, I made a box with dividers which fits ontop of a chest of drawers which means less floor space required and can be removed when she’s out of nappies.
We have a convertible cot as well, but for the moment she’s sleeping in our room in a bassinet, which is good for feeds at night/first thing in the morning. She’s a good sleeper though, so you may want to shift your baby out sooner rather than later!
In Australia there are very firm recommendations about baby bedding for SIDS prevention - so no using quilts or bumpers etc. I swaddle her at the moment in a Merino Kids babywrap, but have 2 Merino Kids sleeping bags for when she’s a little bigger (up to 2). We also bought a stack of sleeping gowns as mentioned above, which open without snaps making night nappy changes so easy.
And finally, if you have cats (we have 4!), this cot canopy may be handy to prevent them snuggling up with the nice warm milky-smelling thing in the cot… We currently have it over the bassinet, but I’ve found our cats in her pram and big cot, so definitely something worthwhile. Other benefit is that it keeps insects away.