It's very intense, basically you live in a constant cycle of:
Baby wakes up, cries.
You change their nappy. Maybe their clothes too if they have wet them.
Prepare a bottle, or get all set up, likely with 889787 pillows, to breastfeed.
Feed them (which can be simple or it can be weirdly frustrating).
Pat them for a while to try and make them burp. This might make them sick which you might be lucky to catch in a muslin or it might necessitate another clothing change for them (and maybe you. And maybe your bed.)
They are then happy and awake for about 15 minutes. They don't do much at this point but they like to gaze intently at your face or any light source.
Then they start to get sleepy. You can either feed them again (if breastfeeding, I would, just because you want to take every chance to get them to the breast in the first few weeks) or you can do some combination of dummy/cuddles/rocking/singing/swaddle/white noise and hopefully they fall asleep. Then you put them down very gently, and hope this doesn't wake them. Or you can let them sleep on your lap. However this means you can't do very much else.
This all will have taken about 60-90 minutes. Maybe a couple of hours if you are unlucky.
They will now sleep (hopefully) for anything from 1-3 hours, maybe 4 if you're lucky. You don't know how long it will be. You are advised to feed at least 8 times in 24 hours, which means waking them at least once every 3 hours (up to 4 at night until they have regained their birth weight). You only have this window to do the following things:
Eating meals without having to be one-handed
Pumping, if you're pumping breastmilk (try to avoid unless you have to)
Showering
Washing everything the baby has got their bodily fluids on, plus your normal washing. Drying the washing. Taking it out of the drying-place so that you can dry more things.
Cooking
Washing up
Tidying up
Driving/taking public transport anywhere
Grocery or baby supply shopping online
Any kind of photo organisation or updating far away family members
Other household admin like making appointments
Taking care of any pets, houseplants or other children
Sleep
Before it all starts again.
Obviously, your partner can do some of these things if you have one (and they ought to!!) but they can't sleep, eat or shower for you, and if you're breastfeeding they can't feed. (But they can do everything else).
Over time the amount of time the baby can cope with being awake for lengthens and rather than feeding like a constant 24-h cycle of nappies, feeds and sleeping, you get a bit of a semblance of a day with naps, and a night with night feeds. I changed nappies overnight when they were first born, but fairly quickly got into a pattern of not changing the nappy overnight unless it leaked or there was poo. With a bedside cot I found night feeds weren't too disruptive.
I also found that I got a bit more streamlined with it and e.g. didn't do the changing bit first unless they had leaked, did the feeding bit first (and breastfeeding gets easier) and then you can incorporate the fun/play/interaction bit into the changing bit, and you get a bit more flexible with the order of things and can work around stuff like being out and about, or put them down in their awake time and let them chill if they are happy to do that.
But the first couple of weeks at least was just this kind of round the clock cycle. I loved it. I love the way everything else seems to fall away and not matter. Some people hate this and find it incredibly isolating. And if you have struggles with feeding or your baby has reflux, those things mess up the feeding part and the getting to sleep parts making them take much longer and be less effective, so the sleep stretches are likely to be shorter as well.