Can I give non-Catholic religious items such as Dream Catchers, Buddhas, crystals, etc?
They are totally inappropriate. Other than that, there are no hard and fast rules about First Communion gifts. Ideally, it should be a gift that does not distract from the meaning of the day. Cold hard cash is a perennial favourite among children, but it’s not terribly meaningful. A toy for a child is enjoyable, but it has nothing to do with this important step in his life. Try to find items that bear some relation to the meaning of the day. For instance, a journal or diary might be a good idea for an adult, who could then use it as a means to meditate and reflect.