I am not an accountant (nor a CPA, nor a lawter).
You should calculate your taxes last. And it is not so simple as you presented it. I recommend you use a CPA for the first several years (and forever, if your business increases).
From the gross, you should subtract all of your expenses plus amortization and what you are left is your taxable income. Now some expenses can have a huge tax implication. for example a remodeling is considered a capital investment and is amortized over 20+ (I think it was 27.5 years) while a repair is considered an immediate expense. So consult your CPA how to do the things in the most tax efficient manner.
In addition you have a real estate depreciation. This is a fake deduction through which you can depreciate an asset (you can only depreciate the building but not the land, so check your taxes on how much is your building cost) over the 20+ years. This will let you lover your tax liability even more. The loan is also not a 100% expense. Only the interest is considered an expense.
When you start your apartment RE investing, I would recommend you to find a CPA that specializes in RE taxes (preferably in RE appartments) and spend 1/2 day with him/her to explain to you how to structure the tings for maximum tax savings. Please do that when you start your business instead of waiting for the tax season (3 months later). During the tax season they are usually preoccupied and cannot spare time to talk(make sure you pay for the consultation). Also some of their recommendations may require an action on your side so if the year is gone, you cannot go back in time to do it.
Property taxes, insurance, utilities are also considered expenses. Driving to and from the property to show it to potential renters can also be considered an expense but you have to keep track of your miles (with date and timestamps matching your odometer).
After all that, most of the buy-and-hold RE professionals are not making any sizeable profit so they pay no or very little taxes the first years of business. Once they start making profit, they 1031 the property into a bigger one(or two) and keep on doing it getting bigger and bigger while having only paper loses.
I can't stress enough how important is to consult a CPA or a TAX attorney when you start. (The CPAs charge less that the tax lawyers).