Hey, Thunder!
I do play ACNH every once in a while, and I am at four stars currently.
Now I don't know any good tips lol, but I will answer your questions the best I can
1) You get a house when you pay off a loan. (I don't know which one, but one of the starting two loans...?)
2) The animals are called Villagers, and you can go ask Wilbur to go on a surprise island, dunno what its called, using a Nook Miles Ticket. However, you need to have an empty plot on your island that's not filled, to actually get a villager.
Hope this helped a little.