House hacking general questions

[Austin Snyder]

Hello I’m a new real estate investor. Last year I bought a large home to “house hack” meaning I lived in the house and rented out the other 3 bedrooms to friends. They paid me essentially under the table. Now I’m moving to another state and want to keep the property and just rent out the 4th bedroom but I’m unsure of a couple things.

Is this a big deal that I didn’t report the income this past year since I was also living there? And also, is there a particular tax form I need to fill out going forward now that this is becoming a full rental property?

Lastly, can I still claim this property as my homestead for the homestead exemption even though my primary residence is technically elsewhere? 

thank you so much in advance for any help!