Hello, and welcome. First thing to tell you is that 90% of parents also have no idea, and are just winging it, same as you. Don't worry, you will pick it up when you need to. Practically speaking you need surprisingly little for a newborn, and just gradually accumulate stuff as they grow. Maybe have a look round in January sales, she what you like the look of.
Broadly speaking you will need
Somewhere for baby to sleep, I went with a cot upstairs and a mosis basket downstairs (they need to be in same room as you for 6 months), but it depends on how much space you have.
Some form of transport, I mostly used a sling when they were little (look up localsling library for great advice), but not everyone gets on with them so you might want to get a buggy as well so you have options.
Some clothes, about 10x vests and onesies in first few sizes and some cardigans will do. Mine didn't really ware proper outfits until 4 months +, so I ended up with loads of bearly warn 'propper' clothes. If you see anything you like offer just get it in a bigger size and store it, you'll thank yourself in a few months time when they've had another growth spurt and you don't have time to shop.
Have a think about if you want to breastfeed, I found it relatively easy and a general fix all (hungry, thirsty, tired, needs a hug - a boob fixes everything) but not everyone gets on with it, and formal is fine too if that works better for you, I'm sure plenty of people on hear will be able to talk you through what you'll need.