I think you should not gamble online because most of them are scams and they will not pay you anything. You will just waste your time. I have seen many sites like this. If you are fond of gambling then to a casino and gamble there with your local currency. You will see everything in front of you. I just gamble for fun and not for money that why I never gambled online.
But we have the provably fair system to verify the rolls which is mathematically stable to verify them and to make sure that all rolls are unbiased and the casino never rigged the rolls. You can gamble on sites which are here for a long time have gained some reputation among the community. New ones though should be examined with caution.
A giveaway if it does not need any type of moneytary investment from your side might be worth trying if you have time.