You do not have to fill in Part III if this is a new corporation formed by you and you own it 100% personally.
Your tax year end will be 12/31
Your ownership percentage wil be 100%.
Let me know if you have any question.
Please note: This advice is provided with the understanding that all the relevant facts have been provided by you. Any change in facts might affect the advice given and hence may not be relied on in such cases. Nothing contained in this reply was intended or written to be used, can be used by any taxpayer, or may be relied upon or used by any taxpayer for the purposes of avoiding penalties that may be imposed on the taxpayer under the Internal Revenue Code of 1986, as amended.
Yes, the company tax year will be 12/31 and your's too.
Part II - you will only select 1 under O para - which is
A new corporation adopting the tax year entered in item F, part I
You will leave the rest blank.