YOu usually can't earn money from them because they are scams.
They are bad people trying to take money from you.
With the internet, home data entry jobs is the newest scam. Years ago, it was "stuffing envelopes". Oh, all you have to do is to put materials into envelopes, and mail them out. The more you stuff and mail, the more you will earn. But it's all a scam. Because they either don't pay you enough, or there are conditions which prevent you from doing enough to earn the money, or it's a scam to just get your money, such as charging you a huge fee to get all the materials, and then you find out it's false.
So probably all the jobs you see that advertise to earn much money at home, is probably false.
There's a saying that has proven out to be true. "If it seems too good to be true, it usually is." this means that if the offer seems to offer big bucks and lots of money to do work like that, then it probably isn't a real job offer, and they're trying to take your money away.
And you being a foreigner are one of the best type of people they get to cheat. You are wanting to start making money, and with your skills and needs, working at home on internet would be the best thing for you. Housewives all over the world would jump at the chance to earn a few extra $$ for their households and yet still stay home to take care of family. But reality is that there are people, dangerous people who will take your money without any consciensce or any guilt. They steal from old people, from young people, whoever they can.
Please don't be the next victim.