smt88's advice about ETFs is relevant, but I'd try to keep it simpler than that, especially if you're talking about small amounts. Think stock and bond mix and get a US and non-US index ETF or index fund for each and leave it alone except to periodically rebalance it or add/remove money depending on external needs.
Depending on what Latin American country you're from you may struggle to find a US based broker happy to take your account. In many countries, a broker will need to have a license in the country of a customer's residence to face a retail customer (this works the other way too, so a German broker would not take a US person's account unless they have an SEC registration). You may be able to get around that by setting up a US LLC or LP to put the money into and hold the account, but that's not economical unless you're investing quite large amounts.
Also if you're considering the tax implications, be aware that the OECD Automatic Exchange of Information applies between the USA and many other countries - so the broker may well be sending tax statements to your home country's tax authority who may send you a bill based upon the income generated by the account, with a penalty on top for not declaring it.