A great place to jump in to both Drupal in general and Drupal 8 Multilingual Initiative specifically, Novice issues are targeted and usually have a well described course of action. Helpful docs: Drupal Novice Handbook Page and Drupal New contributor tasks Documentation Pages. You won't be alone either; post questions in the comments on the specific issue that looks interesting to you, and some of our experienced contributors will respond. Also, live help is available from mentors in the general Core Office Hours.