You're welcome to PM me if you have any questions!
There are ACNL sites that have more or less complete guides to most things you can do in the game, like
this one. Usually, if you don't know how to do something in the game, you can Google it and find lots of information. You can also ask anything here on TBT, people are really friendly for the most part.
To unlock your dream suite, by the way, you need to be the mayor for at least one week. Then, when you go to the town hall, you'll find Isabelle sleeping. If you talk to her, the Dream Suite will be added to the list of PWPs you can get for your town. I think sometimes it can take longer than those 7 days for you to find Isabelle sleeping, so make sure to check every day after you reach that minimum.
To upgrade your house, just pay off your house loan and go talk to Tom Nook. He'll give you the option to make your house bigger and give you a loan for it. Once you pay that off, you can make it bigger again. Once you do that a few times, he'll also start letting you add rooms to your house and even an extra floor and a basement. You can also decorate the outside of your house by going to Tom Nook's shop any time and buying one of the options there (like a new mail box, a new door, etc.) but you can't do that on the day before an upgrade is scheduled to take effect (if you ask to make your house bigger, you then have to wait a day for that to be complete before you can change anything else about your house). After you finish all the upgrades, you can also get one of the upgrades like making your house look like a castle on the outside.
