yo can try mining, trading, crypto investing etc.. All of this requires money to start but you can try free ways like joining the bounty campaign which allows you to earn some rewards in tokens.
And there are variety of bounty campaigns that you can try to earn reward and after you get tokens, you can sell on exchanges to make some money. But be careful, these are not 100% guarantee to help you, and you have to find plans that give you more profits.