Most of cloud mining sites have turned out to be spam nowadays except some sites like genesis.
I have no clear idea about investing.
Trading is the best option for earning bitcoins.Trading could be started even by investing a very small amount.But experience is needed to minimize the risks and losses.
All of them soon will turn out into a scam and even those so called "legit" cloud mining ones are offering ridiculous contracts that there is a slow ROI and you can possibly can't get the capital that you did invested into them. So it's always better to just trade in local bitcoins on any platform that has a lot of alt coins to be bought.