One, and this is the absolute key to financial success, is spend less than you make. 

Hi BP community, I'm seeking everyone's advice.  My goal is to generate $6,000 a month in cash flow in 10 years so I could have the option of quitting my job if I wanted to.  I'm hoping to purchase my first rental pro...

So go through your financial due diligence, inspections etc.. before forming your LLC.

They can ask questions but they listen and learn.I review buyer financials before we start working together.

I have been a home owner for 8 years and I have always paid an additional ~10% of the monthly mortgage every month towards the principal of the loan.Any thoughts to whether or not this plan will help achieve financial independence sooner, or should I put this 10% into building a real estate fund?

You will want to check with your financial adviser as it may not make sense to hold the property in the IRA if you intend to later take it as an in-kind distribution because of taxes.

My dream is to have rental properties (Single or multi families, apartments etc) I think it is a better way to become a millionaire and achieve financial freedom.

@Mark ZarragoitiaNonbank Trustees and CustodiansA financial organization not described as a bank under IRC Sec. 408(n) also may be eligible to act as an IRA trustee or custodian if the IRS grants the organization nonbank trustee or custodial powers.

I don't plan to ever sell it as it'll make a great rental when I'm done living in it years from now, but the excellent financial aspect of it's appreciation was pure luck of timing.

Towards end of 2016, I set a goal for 2017 to save $50K for real estate investing so I took a part time job + selling on ebay... really worked hard, but only reached half my goal because of my other financial responsibilities.