How to do you do your due diligence?

[Justin Cabral]

Newbie here trying not to overextend myself. 

So lets say I have my eyes on a property. How do you go about determining your monthly nut (as far as taxes, insurance, and maintenance)?

And once you have that figure, how do you get a "hand grenade close" estimate of what you think you can gross as a STR? Is it a manual process (what does that look like)? Are there any online tools (what does that look like)?

This would be my first one and the property alone will cost between 1M and 1.5M so I want to make sure I do my due diligence and minimize getting caught with my pants down. 

Thanks in advance for any guidance you can provide.