How can one invest in US the market?

Adding on to what Gabriel mentioned, do consider the right broker as well. I'd avoid the local traditional brokers as the fees are not competitive. For US market, I'll suggest looking into Td Ameritrade or interactive brokers

Open a brokerage account.

Fill up a W8Ben form, your brokerage sign up process should include it. Just let them know you want to invest in US markets.

That's basically it!