It is possible in the crypto world to earn some decent money without investing although you got to work hard for it. You can join some airdrops and bounties which you can then sell and invest on coins you like. There are times that the bounties itself are also good investments, so, it's up to you whether or not to sell or hold them.
If you want to quickly make a lot of money with the help of crypto currency then it is better not to invest as you will likely remain in a big loss. Here you need patience and careful analysis.