My DD was in vest and baby grow for a LOT of the first year, definitely until she was cruising/walking. They are comfy, easy to clean and don’t get in the way of anything - some outfits for girls are a bugger and look silly when you’re strapping them into a 5 point harness on the pram or trying to get the into a carrier. There’s plenty of time for outfits when they are walking, and mine still wore baby grows at night until she was nearly 2 as they keep feet snug and don’t expose tummy (DD was a wriggly sleeper, her pjs end up right up around her armpits now some nights!)
You need more vests than anything else, because nappies will sometimes leak, especially if they do a poo when they are in the pram/car - they wriggle and it gets squished up the back! I found short sleeved ones much easier as sometimes it’s a pain getting a long sleeved grow over a long sleeved vest, so we only used the long sleeved ones on really freezing days.
Snowsuits are amazing, but only once they’re walking. When they’re little, it’s much easier to just layer them up with blankets and such, then you can easily adjust if they are too warm-cold. I had a lovely snug sleeping bag thingy for the pram for when DD was going on on super cold days, all lovely and fleecy so she didn’t have to wear anything extra over her baby grow.
In summer, you might want to just pop leggings on over a vest, but for a November baby id just get newborn and 0-3 months ones in plain colours. You can get multipacks in any supermarket. I’d hold off getting bigger sizes just yet - you don’t know how long your baby will stay in each size, so it’s not obvious what the weather will be like when you move up a size.
How much you get depends on how often you want to run your washing machine. On a poopy day, you can easily get through 3 or 4 vests! Most days you won’t though. My mum advised me to buy enough that I felt I wouldn’t have to run the washing machine more than every 3 days - that way there’s time for stuff to dry without a panic!
I’d strongly recommend accepting hand me downs of things like vests. Nobody will see them anyway, and some of DD’s things she only wore a couple of times because of random growth spurts. It feels like such a waste packing something away that’s only been worn twice!
A nice soft cotton hat or two is worth it. Remember, they don’t have much hair and have sensitive skin, so a woolly hat is probably just going to annoy them.
Socks are pointless for tiny ones. You just lose them EVERYWHERE. Gloves too.