Weapons Don't have effect on the enemy

whenever I try to test my game and attack, I use a weapon then it just says "there was no effect on enemy" please help! thanks

What engine are you using?

I am using RPG maker MV as my engine

I've moved this thread to MV Support. Thank you.

that message means that the skill used in the effect is too weak to do anything on the enemy.
If you're new to the RPG-Maker than the most common cause is that you removed or added the wrong traits - for example by removing all actors and creating your own without checking first what data is needed for what.
Or that you changed the skill #1 which is always used on attacks

Please give a screenshot of
1) the enemy you're fighting against
2) the attack skill (always skill #1 in your database, no matter how you change that skill)
3) the actor and its class
4) the weapon (if equipped)

this happens to all my enemies but here

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.