I would offer the following advice about starting in real estate investing.
1. Don't worry about doing everything perfectly right. You will make mistakes. We ALL do. Things will go wrong and you will have to adjust.
2. Whilst it's important to run the numbers and understand what they mean, you really only need to pencil out the broad parameters to give you some semblance of comfort that you won't lose your shirt.
3. Trust your instincts regarding the basics. Most people can use good judgement to gauge what is a good house, what's a good neighbourhood and whether someone would want to rent your house. As you gain more experience your instincts will guide you on more sophisticated parameters.
4. Focus on a scale and type of real estate investing that minimises the variables and makes it easy for you to digest. You only need to understand and absorb the information that's relevant to what you find interesting. Forget the rest.
5. Here's something I used to worry about a lot. How do I know what a good deal looks like? I learned that it frankly can look very different to different people and if it looks good to me then to go with it. Why? Because everyone has different objectives and targets, different likes and dislikes, are at different stages of their investing journey, have different financial situations etc.
I hope this helps and I wish you the very best of luck with your investments !