ConverseWomen's Chuck Taylor All Star Shoreline Knit Sneaker

What size do I get if I'm size 8 in women's? Is it by men's sizing?

Is it womens size "medium/10.5 b (m)? why isn't specified like the others size listed?!

What color is athletic navy? They don't have regular navy in my size.

What does the M and B stand for?