if i am learning 2 languages and my goal is 20 xp then do i need to do 20 xp in each language or 20 xp in total???
20 XP total. It doesn't matter which languages you're doing. The daily goal means how many XP total you need.
20XP total is valid for the global streak (orange flame), which you can "streak freeze" or repair on the mobile apps.
However, there are "individual language streaks" per course, which are hidden on the website (they may be visible on the app).
The user script "DuoTweak" could read / display those in your profile (you need the
duo.old_web_url_whitelist=["^.+"]; workaround to enable the old script which is not compatible with the new Scala 2017 portal anymore) and you have to practice daily these courses to continue the individual course streak.
But I am unsure if you need to match your daily coach goal (20XP) for each course to maintain these streaks....I would say probably.