So, I had a fleet enchantment put on me at last event. But now I can’t attend the next one. Does this mean i lose these materials, or can I send them to someone, or are they kept aside until I go?
You will get them at the next event that you attend.
You only get the resources for the downtime immediately following the last event you attended - so yes, you’ll get your buffed resources, but not any from any following missed events.