Men's Van Heusen Flex slim fit stretch white dress shirt

Men's Van Heusen Flex slim fit stretch white dress shirt. Purchased at Khols for a Halloween costume, worn once (I'm a woman but dressed up like Blues Brothers with my kids). Pictured is a small yellow spot on the right sleeve and a mark from the tag adhesive on the left front. I don't know much about men's dress clothes so I'm afraid to ruin it trying to wash it, especially with well water. Not sure if the tie came with it or not but it will be sent with the shirt.