The MountainUnisex Native Wolf Spirit Hooded Sweatshirt T-Shirt (pack of 1)

I wear a women's size medium, but I like wearing T-shirts or long sleeve shirts underneath, what size should I buy?

Is the image only on the front?

I have 2 questions, (1) is this an actual hoodie? (2) Does this sweatshirt run bigger or smaller?

How thick is the material?