They have helped a number of investors improve there score.  

They all look to have good credit scores except one. 

I have close to an 800 credit score and no debt besides student loans (10k).

But, we have since brought our credit scores from 400s to 750+ and three houses. 

@Charlie MacPherson does it require a good credit score to wholetail or buy and retail?

When I turn 18, would it be a good idea for me to start working my credit score up above 580, save 3.5% for a down payment with an FHA loan and try to buy income properties asap?

In order to properly educate yourself and secure your loan, you should do a few things first, like checking your credit score, finding out what your property is worth, do some research, shop around, determine what kind of second mortgage is best for you, and always be sure to read the fine print when signing.

You can borrow the lesser of $50K or 50% of your vested plan value in this case. 

My credit score is great, and I've been doing a lot of self-educating via BiggerPockets, local meet-ups, various podcasts and books, and networking with great local investors.

(trying to save time)2) If I need to fill out loan applications for each lender, will this affect my credit score negatively?