Additionally, strong tax planning is essential, as your W2 income limits your ability to deduct passive losses.

When my wife and I started out we new we wanted to invest but did not know how to, we took action and unfortunately found a family friend realtor (amazing learning experience) then we found bigger pockets. 

You'll want to incorporate interest costs on the HELOC while you're using it, but that will add to your holding costs in addition to utilities, closing costs, etc..

I recommend that you work with an accountant that has experience with real estate taxation and partnership tax returns. 

@Walter PinedaEven if someone give you a referral, what meets their expectations, may not meet yours.In our experience, the #1 mistake owners make when selecting a Property Management Company (PMC) is ASSUMING instead of CONFIRMING.It's often a case of not doing enough research, as they don't know what they don't know!

Many investors budget an additional 5%–10% of gross rental income for CapEx, though this too depends on the property’s condition and the age of major systems.

There is so substitute for experience.

My templates are built from real-world experience – check my profile (notion4agents.com) if you’re curious.What’s your favorite way to stay organized in real estate?

I find single ADUs are mostly being added by people with minimal RE investment experience often without a clue as to the value that will be added by the adu addition.  

It is much better to have a reserve fund and add it monthly.