I don’t make (a lot of) money; do I still need to report to the USA?

Yes. Even if you have no earnings, it does not always dismiss you from filing taxes in the US; it will most likely result in you not paying any tax.

Basically, you have to file an IRS Form 1040 for the previous year if your income was above a certain threshold. These thresholds are the same as for US residents.  For tax year 2019 (filing in 2020) the thresholds (total yearly income) are:

Status Under 65 65 or older
You are single (unmarried) $12,200 $13,850
You are married filing jointly $24,400 $25,700
You are married filing separately $12,200 $13,850
You are filing as “Head of household” $18,350 $20,000
You are a widow or widower with dependent child $24,400 $25,700

Important note: Certain government subsidies such as child benefits, unemployment benefits, and subsidies are regarded by the US as reportable income that might make you reach the filing threshold.