How do you get more stars?

You need to visit this hotel.. It amazing! Please visit the art consevitory inn! I hear she offers you some great deals... like stay at me and leave a commit and I will visit you 3 times!

You get more stars when you change the standard of your hotel, and then you can build rooms of a higher standard.

Yes, she is correct.
To earn more stars, you must raise enough money to change your hotel standard.