Seth Klarman, in Margin of Safety, is refreshingly clear on this. The aim is always to buy something worth a dollar, for less than a dollar. You, not the market, must determine what the asset is worth. That generally requires a significant amount of investigation.
If you are not up for that, Klarman explicitly notes that index investing will be fine, but not spectacular, and in particular the index will trade in stocks for no good (investment) reason but simply because they have to keep the index balanced.
Trading on news and events is essentially gambling, although you can use other people's reaction to news to time investments so long as you've already decided to invest and were simply waiting for the price to meet your criteria to make the trade.
If you are not up for that, Klarman explicitly notes that index investing will be fine, but not spectacular, and in particular the index will trade in stocks for no good (investment) reason but simply because they have to keep the index balanced.
Trading on news and events is essentially gambling, although you can use other people's reaction to news to time investments so long as you've already decided to invest and were simply waiting for the price to meet your criteria to make the trade.