Yes, your expenses are deductible regardless of if you report your activity as a rental or a business. To qualify as a business, you'll need to meet the criteria of a "Real estate professional".
The only advantage of this is that the losses aren't limited to $25,000 or phased out over the income limitation. The expenses deducted don't change.
To Qualify As A Real Estimate Professional (see attachment from the learn more button in TurboTax at the start of the rental section you're are asked these questions):
Note that you can deduct all of you expenses on schedule E, reducing your rental income. As rental income is passive income, you usually cannot take a loss against all other types of income. However, there's a rental property exception that as long as you actively participate in managing the rental, you can take up to a $25,000 loss against all other income. However, this deduction is phased out over total personal income of $100,000 - $150,000.
Based on this added info, let me know where you're at and your follow up questions for more assistance.