OK quick lesson.
MCN come in a few varieties with a myriad of brands;

Prefolds - basically a square of bamboo or flannel that you fold and either secure with a snappi or just a well fitting cover. THey all require a cover.

Fitteds - there are made of absorbent material only (bamboo/cotton/hemp) and have no waterproof outer, therefore always requiring a cover.

Pockets - are basically a shell that is the waterproof outer and a fleece inner that looks like a nappy. There is an opening at one end to have stuffing placed inside (the absorbant bit). There secure with snaps or velcro and come in both sized and OFSM. You can generally adjust the stuffing to your bubs requirement.

All In ones - are exactly that all the waterproofing, inner and absorbant bit in the one nappy. No stuffing or folding required. Downside is that they take much longer to dry.

All in Twos - similar to AIOs but usually have part of the absorbant bit that either snaps or folds out to make for a quicker drying time.

Covers - come in fleece, wool or PUL. PUL is great for day but too hot and less breathable for night.

Myself I prefer fitted for a newborn with covers. Many of the OSFM are far too big I found (and my bub was over 4kg at birth).

There are so so many brands. Many of the MPMs on here either make or stock them. There is a cloth nappy discussion as well where you can get many great recommendations.
My favourite fitteds are Spunky Butts hands down for newborns. If I go back for a third I will stock up on them.

My fave covers are Maz-a-licious covers and BBH PUL covers.
I also love my hand knitted wool shorties.
Many recommend BBH fitteds and I love them too - but my littlest bub is 1 and finally now they fit him great. I found them far too bulky for smaller babies.
As far as AI2s go my hands down fave is Bundles of Buns. They are made to order.

I don't use liners unless we have issues - then I just use rectangles of microfleece.

As for numbers I have culled but still have about 50-60 nappies. Trust me you won't need that many. Babies need changing about 10-12times a day so about 25 should do until you figure out your system.

My number one tip would be don't buy all one brand. You never know how they will fit and if you get all the same and they don't fit properly - you've wasted your money. Even on my two kids different nappies suited each of them differently.

HTH a bit.