Do you think it's okay that I give my 10% discount to all the customers who come to my line?
I'm not sure. Why do you feel like sharing your discount with everyone?
I just think it's a fun thing to do.
It can be a nice gesture to share your discount with other people, but you could end up in trouble if you abuse this perk. Employee discounts are typically only meant to be used by an employee. If upper management becomes aware of what you're doing you could get fired.
But they said I could use it for friends too.
I'm sure they're fine with you using it for your friends, but probably wouldn't be too happy to find out you're using it for everyone. It's not right to take advantage of your discount like this.