You are spot on: not considering annual increases for every property is a cardinal mistake. 

I'm 20 and this'll be my 1st buy and hold so don't want to make any rookie mistakes.

Recommend 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.

@Jeff EbertRecommend 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 also welcome things I should know and mistakes you may be open to share so I can have a better idea of what to expect. 

Possibly take some cash out at the same time if the LTV and equity are within range.No, It is not normal for "Banks" to make this mistake usually its a "Lender" or smaller "Mom & Pop" broker shop.

I'm looking at home equity loans for another rental property we own currently.More than likely, we'll have to put the property back on the market and find some cash to cover the difference between current construction draws and sale price.It's an expensive mistake - but we'll be back again to fight another day. 

We can share stories of mistakes and timelines that have been made along with great successes with servicers over our past 10 years. 

Bigger Pockets has a wealth of information and the forums get you even more information that can save you from making a mistake. 

Lot of people are going to tell you go for it and build your team later but that’s a huge mistake.