That sounds like a lovely meditation Pandorra
As a Wiccan, I use a brown or green candle to represent the earth, nature, etc - so a green pixie and green energy from the tree explains that.
I think the young man handing you the medal/coin will be something personal to you.
The black shadows, I would think of as 'protectors' and as the man then became your guide, I am guessing he sensed your fear and appeared so as to put you at ease.
Red flowers - Love, passion, good health, energy, action, vibrancy. (We use red in spells for physical strength, love and passion) and red also relates to the root chakra - some people visualise the chakras as flowers.
The snow covered mountain, which you saw change into a volcano, could also represent something personal to you - such as a problem that seems like a mountain to overcome.
I hope this helps you make sense of your meditation.
Did you speak to your Wiccan friend about it to ask her opinion?
Love Raven xxxxx