To download Stata on a Mac, go to the official Stata site, but you’ll need a valid license (individual, student via university, or trial). For most students, check your university’s software download page first. Then choose the correct version (Apple Silicon if M1/M2/M3, Intel otherwise). Install, activate, and run.
(e.g., Stata 18.0 to 18.5) happen within the application and do not require a full re-download.