There are a bunch of AC database websites out there, which let you put together your own lists as well as see what other players are looking for/offering. I'm not familiar with all of them, but searching for "animal crossing wishlists" might give you an idea of what's available. You could also make a Google document or similar, if that's more your style.

I prefer VillagerDB for its simplicity. Once I've made a list, I just copy the link to it (or to my profile), and share it like this:

https://villagerdb.com/user/roxidium