Otherwise, it's not worth the time learning, because you do have to make mistakes. 

Any mistakes to avoid?

@Gabriel Alvarado several times in the past, we've found that many agents make the mistake of using their sales tools for rental situations.#1 mistake is not using the right advertising websites correctly.So, ask your agent for a list of websites they are advertising your properties on.May also help if you post JUST the address here - we should be able to do a web search and find it - or there's an obvious advertising problem!

You will make mistakes.

@Ming Li HerreraRecommend exploring as many sources as possible to get referrals AND cross-reference them to get as much accurate information as possible.Check out NARPM.com, BP’s Property Manager Finder (BiggerPockets: The Real Estate Investing Social Network), etc.Also, encourage you to learn from the mistakes of others - by reading posts here on BiggerPockets about owners not having their expectations met by their current Property Management Company.

I had no money when purchasing so I skipped inspections which was a big mistake.

I had no money when purchasing so I skipped inspections which was a big mistake.

I am VERY certain I have made some (or many) mistakes or left money on the table or overpaid etc... but all of these deals are cash flow positive after all costs + vacancy and maintenance. 

@Thomas SehonRecommend exploring as many sources as possible to get referrals AND cross-reference them to get as much accurate information as possible.Check out NARPM.com, BP’s Property Manager Finder (BiggerPockets: The Real Estate Investing Social Network), etc.Also, encourage you to learn from the mistakes of others - by reading posts here on BiggerPockets about owners not having their expectations met by their current Property Management Company.

Not to mention you will present yourself far more professionally to prospective business partners, lenders etc. who will be necessary for your growth.The next mistake you appear to be making is equating number of doors to growth.