To be more specific, there are currently no change fees for trips which begin in North or South America -- https://www.aa.com/i18n/customer-ser....jsp#ticketing
There can potentially be a change fee if you book trips which do not originate in North/South America.

For credit to remain valid, travel must commence (but not necessarily be completed) within one year of ticket issue date (note, it is based on issue date, not original flight departure date). Rebooking a new flight will not extend the validity date of an existing credit.