"I'm a green card holder. "How can I bring my mom and daughter to the U.S.?"
You're not going to be able to bring your parent as a green card holder. Parents can only be petitioned by U.S. citizens, so you will need to naturalize yourself. That's something we can help you with, or you can grab form N-400 and look through that. Once you are a U.S. citizen, you can then petition your parents. There is no quota for parent visas.
You can petition for a child at any time, even as a green card holder. So that part's pretty straight forward and very common. How long it will take depends on the age. For a minor child, it's going to be much much quicker. And it also depends, if the child is not a minor, it it's an adult child, it's going to depend on the country. Some countries have a waiting list that's over a decade. Other countries are quicker. There's a quota per country.