There are many ways to earn cryptocurrency without investing. I would suggest the best way to
earn free cryptos is by joining the airdrops.
Airdrop refers to the FREE coins (free bitcoins/free crypto) given during the Initial Coin Offerings - ICO of the crypto companies in the holders' wallet in order to publicize their tokens.
but very little Airdrop really pays bounty hunters so if I personally focus more on signature campaigns because I think there is more potential to get prizes.
but if you still insist on following Airdrop, my advice is that you have to follow a lot of Airdrop so the chances of getting a prize will be greater.