If your LLC is registered as an S-Corp with the IRS, then yes, you will need to file a Form 1120-S even if you had no income or expenses during the year. As RobertB4444 previously mentioned, if your LLC is taxed as a partnership, there wouldn't be a filing requirement. Rules are different if your LLC is registered as an S corporation with the IRS. See the following for more information, IRS Frequently Asked Questions.
Regarding your W2 income, you will need to file that separately on your personal return.
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