Zenith39 welcome to the community, it's good to see more people moving from iOS to GOS.
Apple's not gonna make it easy for you as they actively work against user experiences outside of their eco system. My advice would be to keep your Apple tech around for a while and make the transfer one device at a time to avoid uncomfortable surprises (eSIM transfer might be your biggest obstacle). You have plenty time and we're here to help, so take it slowly.
As for trackers, unfortunately there's just no real competitor to airtags since the Apple mesh network is so large and Apple doesn't let iPhone users opt out of it. The closest Android alternatives are Tile and Samsung trackers and they just won't perform as well. In the long term I suggest you leave trackers behind for the reasons you mentioned, but in the meantime it might be worth it to keep your iPhone and airtags (maybe locked away until you really need them).
Hope you'll find your pace and have a nice transfer. On the bright side: There will also be many moments where you're like "Wow, this is such a cool feature, why didn't Apple let me do this?".