Work on your Clairaudience and Clairvoyance chakras, and your astral senses, it can take much time to be able to accurately know who your Guardian is. When you greet them, make sure to be respectful and remember to thank them for guiding you and protecting you.
If you're not that advanced yet, you can use divination to find out. On the ToZ website, all the guardians have Tarot cards associated with them. You can ask your guardian to help you pick their card. If you want, you can use a pendulum to confirm the chosen card.
This will help clear up misunderstandings and misconceptions regarding our dear Guardian Daemons. 1. You do not choose your GD, they choose you. They are far more advanced, wise, and psychic than we are, they know more than you do about yourself and what you need in order to advance. As you...
ancient-forums.com
All I can tell you from experience is that the Guardian Demon is always with you even if you don't know him or her and will show up when he or she sees fit.
You can still talk to him or her by calling him or her “Guardian Demon.” You will see that as you go along the path you will get to know.