How to wash it and how to take care of it?

Wash on cold and let it air dry. Dont wring it out or anything just spread it out over a wire, chair, rack or whatever and let it dry and it should be good.

how do you wrap it like in the picture???

what I did was go onto Youtube and check out videos there... there are many other ways to wrap it that's what makes it so cool and practical... also the fabric is awesome and so comfortable... not itchy...lol ... good luck

Is it made of 100% cotton ?

It's made in China so most likely it's NOT 100% cotton. I'm guessing it's a blend of some kind. There are 100% cotton Keffiyeh's out there, it takes some looking.

Is this good for airsoft to protect against BB's and good with sweat around the neck?

It's not super thick so I don't think it would do anything to protect against impact from BBs. Might not hurt AS much though. Will definitely catch the neck-sweat!