Shyness in flirting/never dated

How do you flirt? How do you show someone you like them?How do you know if someone likes you?I've never dated, never had a relationship. Don't really know why. They say that this type of fear of relationships is actually a fear of rejection/abandonment. I don't know.I know i want to get over it though. How do i get over the fear, nervousness, and self-shame?Has anyone been here? Anyone have any ideas?