Already have fantastic help, going through the links and reading up is great.
For hair common places are Dollyhair.com or mylittlecustoms, there are others so shop around.
Paints anything that is acrylic the better brand you can go for the better, Folkart is a good brand as any.
Paintbrushes - a range including tiny ones if plan small detailed work and good for doing the eyes.
Sculpting - apoxie is well known, I personally use milliput as easier in UK, fimo and baked sculpties are different to use so it depends if you want air dry etc
Tools - Wire, tag ties and threads/needles for rehairing, highly recommend you read the linkies above to pick a method of rehairing and stock up ready!
Sealant - to seal painting down whether it be full body repaints or sealing detailed painting, highly recommended on here is Modge Podge if you can get it depending where from. Otherwise varnishes that are for use on acrylics, Dullcotes is a good other brand and these come in Matt, Satin, Gloss etc.
Glue - to seal hair ends though if get modge podge it is multiple use here.
There are many many other tools and you will build it up as needed, the community at large is fantastic at guiding to brands and tools needed so best of luck!