My best tip is to stop using the calculators and make friends with a local realtor who is also an investor. This way they won't mind taking you to see investment properties. The calculators mean nothing until you see what 100k looks like, 200k, and so on, and until you get familiar with what repairs are like in real life the calculator is just an old school video game.
Get your own buyer's agent. If you don't, you will get taken for a ride by the listing agent whose primary duty is to the seller. Yes, allowing them to double-end the deal can help you win, but not when you are new.
If you are going to live in the unit, you can go as low as 3.5% down for an FHA loan. If you are only looking for an investment, you will need 20% most likely. If your rental is set up the right way, you have the tenants pay for all of their expenses.
Too many new investors are spending too much time calculating properties online, but until you see them you don't know what figures really are. Also, the biggest problem with the calculator is that it will allocate a monthly allowance for repairs, but when you buy an investment property, something always breaks right away and it's big. So you need 5-10k reserves on any first deal to be safe and that won't be in the calculation.