Mortgage and a Job? NO WAY!

Once you get the map from Pelly the Clerk and enter your own home and exit the home you will not be able to move at the start of the exit because Tom Nook will be greeting you!

Once you get to make a convo with Tom Nook he will make an introduction and will offer a job to deduct your mortage from 19,000 to 18,400 bells

Complete the Job by delivering posting stuff on the bulletin board at town hall and sending letters
then you'll be able to do what EVER you want on Animal Crossing : Wild world!