To get into the US on a Visa you a) are brought in by a family member, there is a long ass line
b) are highly skilled in some field, being a doctor, a scientist, an engineer, particular professions that are highly desired, this requires a job offer from an employer*
c) you sign up for the lottery (individuals from certain countries need not apply)
d) you're a refugee (but only so many of you get in)
e) tiny numbers of very specialized other cases including non-clergy religious etc.
*there are 10k "Unskilled labor" positions available, of which no more than 7% of the total - 700 - can go to one single country. This includes any dependents that the individual may bring. So what, 200 unskilled Mexican laborers per year? Maybe? Assuming a family size of 3.
This shows the back logs for the types of Visas, the feds don't even report the unskilled backlog.
Permanent Resident Card
More resources for you:
How hard is it to immigrate?
How long does it take to get a green card
TL,DR: If you don't have a job, a family member who's a citizen or have 500k to drop, you're SOL