The blue icon at the top of the screen says I'm under protection. What does that mean?
When you play Edgeworld for the first time Admiral Tenmu extends a shield over your base, protecting you from attack.
This 'beginner protection' lasts for three days. During this time, you can build up your base, improve your defenses, and attack the bases of the three factions.
If you attack another player Tenmu will realize you no longer need his help and your beginner protection will go away.
Play hard during your first three days to build up a strong defensive base!