Just buy a SPY index fund and hold it. As the recent episode has shown, even 2X leverage is by no means safe over the long term. You'll probably do better than 95% of the people who post on these boards.
One of the biggest deceptions pulled on the investing public, historically, is the ROI of "the market." Well, "the market" consisted of stocks only, not indices, for most of it's life. The Dow Jones 30 has had the individual stocks replaced over and over during the past 80 years or so. In fact, the only original stock is GE. So, since you could not invest in the DJIA, only individual stocks, there was nowhere near a 10% return as "advertised." Now days, yes, you can invest in indices, replacement stocks and all...but then you need to think about that good old "timing" aspect to it. So, yes, you can get 10% and more if your timing is good...otherwise very doubtful. As to "what" to buy....keep it simple...go after stocks with the best "price to book" - which reflects what the company is really worth instead of fanciful financial projections. The lower price to book, combined with current earnings, is a good way to go. Don