as I assumed - don't delete data unless you know what to replace it with.
Your attacks do no damage because you set your attack to do zero damage in its formula - no formula is the same as setting damage to zero.
Additionally, making your attack skill always requiring a sword will disable the attack for anyone who has no sword, that is also a very bad idea.
Besides - why do you want the effect of an attack to be that the enemy learns how to use the attack skill? Enemies never learn skills (they use action patterns instead).
Start a new project - that project you made the screenshots from is completely broken and since its mostly empty you're better to have the correct data restored by making a new project.
And then take note of what is inside the different fields to learn what is needed before deleting everything.
I also suggest you follow the links in my signature to the starting point and work through the tutorials listed there to learn how the engine works.