A digital marketing intern should understand the fundamentals of audience research, positioning, content, search, paid media, analytics, and reporting even if they are not yet advanced in every area.
Before starting, practice using spreadsheets, analytics concepts, keyword research methods, basic copywriting, and clear presentation. Learn how to organize files and document assumptions because marketing work often passes between several people.
Most importantly, develop the habit of asking what business objective a task serves. Publishing content or collecting keywords is not the final goal; each activity should connect to a larger outcome.
Internships then become a place to apply and deepen foundations rather than encountering every concept for the first time.