I have to show the house anyway and give them keys once approved.I make them go to my bank and deposit rent directly to my account.

Would love to get schooled and see if there are things I still need to account for.Mahalo,Matt

Were you to do this your entire IRA account (the account that purchased the property) would be considered to be immediately distributed in full and you would owe taxes and penalties on the full amount.

Anyway, the many questions I have:What sort of business checking account do folks use? 

I’m not a lawyer, an accountant or a cpa.

I am 18 and don't have money to spend on getting a pro account so I am making my own calculators in excel. 

@Tavia King I know a great accountant in Dallas.

You should then receive a physical collateral file if not already an electronic one - Collateral file is a a file which contains all of the previous mortgage paper work including things like alonges, deeds, borrower personal information such as bank accounts and credit scores at the time of the sale, pretty much all the paperwork submitted, required at the time of the sale. 

Money Mustache and the recession for getting us started on our real estate journey, and our gainful employment for saving up a bunch and the stock market (betterment account) for giving us an extra $10k or so for free.

Personally, I like to max out my Roth IRA for the tax advantages and protection that retirement accounts have.