LLC tax and ownership questions

[Yi Chu]

Can someone help me with the following two questions? 

1) If you set up an LLC (with an EIN from IRS and approval from state) but it turns out you don't have any business during the year, how do you report that for your federal and state tax return in the following year?

2) How do you change ownership of you LLC for at both federal (IRS) and state levels?

Thank you!