If you live somewhere with a good variety of different cultures, most of them probably have an association of some kind, which often host events that let them share their holidays and traditions with the larger population. Try to track down their local event calendars and show up whenever you can. I live in a medium sized city with decent sized Hispanic, Indian, Vietnamese, and Native American populations, and between the lot of them there’s ALWAYS something going on - and for me personally, 99% of it is stuff I’ve never even heard of, so it’s a completely new experience every time (vs trying to drag out the more familiar holiday feels by leaving the xmas lights up until March lol).