Yes, you must file an 1120-S (S corporation income tax return) regardless of whether or not you had any sales or income.
See https://www.irs.gov/instructions/i1120s#idm139641016872208
You can deduct expenses incurred at such time (and after) you were officially open for business. Costs incurred prior to opening can typically be deducted as start-up or organizational costs.
