The best preparation you can do in my experience is find out beforehand where you can get support. Whether that's a local bf group, HCPs or paying for a private lactation consultant. Because the biggest thing about bf is that it's bloody hard work. Babies do not know how to latch intuitively and nor do mums. latching and positioning can be a complicated business and it really matters that you have places to go for help if you need it. And straight from the get go rather than trying to find this stuff out when it's 2am, your hormones are going crazy and you have a screaming baby who won't attach themselves. Bf groups are great because someone will sit and watch a whole feed, not just the couple of minutes a midwife or whoever might have available to say oh yep looks fine and when 5 mins later it's not so much when theyve pulled seemingly for 'no reason' (there's nearly always a reason).
Learn about things like tongue tie and mastitis. They may not affect you but give yourself a heads up in case. Also loads of HCPs moss tongue tie so if you think it's an issue be assertive and know who to go to that is trained to assess, not just any old midwife or GP or HV, lots of whom really don't know. Don't leave mastitis or the early signs if it's brewing (engorged boobs, feeling a bit fluey etc). Know what to do to nip it in the bud so to speak. Otherwise get to the GP pronto.
on a practical level I really wouldn't bother With a perfect prep or any electric breast pumps (advice is not to express anyway for first few weeks until your supply is established so you have plenty of time to go and buy one if you want to). (you may also want to look at some of the hygiene studies of the perfect prep - bit gross). I would suggest getting a let down pump, such as the nature bond or hakka. These are cheap (£10 roughly) devices that suction on to your boobs. The idea is when you feed from one boob you bung it on the other and it catches the let down (leakage) that happens naturally when you feed even if there's no baby on that nipple. You can build up a fair whack of milk this way if it works for you (not everyone gets on with them) and it has less impact on supply. I've also got more out of my boobs with a let down pump than with a decent hand pump or a very very expensive medical grade electric pump. If it doesn't work for you, you've wasted a few quid. Not hundreds. Bonus is that it's hands free whereas manual pumps take two hands and electric generally one (unless you wear a pump bra). You really need your hands for babies and eating and other essential things so anything that gives you your hands back is great. You can just squeeze your boobs in your hands to get milk out but it's quite hard on them.
Second the advice about Amazon prime too so you can get supplies the next day.
What I would suggest beyond the above:
Your nipples will hurt in all likelihood. Get a good nipple cream. Lanisoh is the one most people swear by.
Also hydrogel pads. They are expensive (works out about £2 a day as you throw away) but my god if you have sore nipples they are worth their weight in gold. keep in fridge for extra cooling. lots of people haven't heard of these. They do not absorb milk so you will need some sort of breast pads over the top. They purely stop your nipples from feeling like they'll fall off.
I personally hate the regular breast pads like lanisoh ones as they ruck up in your bra over the course of the day and not very environmentally friendly. There's loads of reusable ones that are much smoother and softer on your nipples, you just stick them in the washing machine..
snacks. Bf makes you very hungry and thirsty. Keep lots of food to hand with things like cereal bars, chocolate, nuts that you can shovel in your face at 4am or when you're glued to the sofa. Also drink lots.
Get a decent nursing bra. Preferably one that doesn't make you feel like a sack of potatoes. You may prefer to be naked at home but if your boobs leak you either need a cloth under them or a bra to put the breast pads in.
bf out and about without a nursing bra would be a massive pita.
Muslins. Get more muslins that you think would ever possibly be needed. Babies sick all the time and you will be forever grabbing a new muslin after feeds (depending on how sicky your baby is or how high your tolerance is to the smell of baby sick). Cheap ones are fine. many are white which is boring and the colourful ones or ones with animals etc on cheer you up a bit when you're mopping vomit again.
Please remember what I said at the start though. It's so hard. Your milk won't come in for 2-5 days (you just have colostrum to start with) and the whole first few weeks can be a nightmare. There are very few a people who can't bf for a physical reason. Usually it's issues that would be fixable if only they had the right support. You can go back to bf even if you give a bottle initially.
Good luck!