Typically, when someone is "tapped" by a God or Goddess, there is a series of messages, rather than a single isolated incident. Many of these messages are symbolic in nature, rather than actual "Hey! I'm Athena! Lookit me!" kind of things.
As an example, you might have a dream or vision in which you are approached by a human figure who has something different about them. You'll probably know it's a deity, but they are sometimes evasive when it comes to telling you who they are - so you could do some research, and figure out who it was based upon appearance and characteristics.
In addition to a vision, you might have an experience in which symbols of this God or Goddess appear randomly in your daily life. Perhaps you've never seen an owl before in your area, and now one has built a nest above your back yard, or someone gives you a gift of an owl statue out of the blue - owls could represent Athena or Blodeuwedd. Pay attention to repeat occurrences, and see if you can determine a pattern. Eventually you may be able to figure out who it is that's trying to get your attention.
Bear in mind as well that raising magical energy may heighten your awareness of this sort of thing. If you're someone who raises energy a lot, that may leave you far more open to receiving a message from the Divine than someone who doesn't do much energy work.