How to give my enemy a certain amount of health?

Hello! I’m a very new beginner, and I could only find tutorials of killing enemies in a certain amount of hits, but I wanted to know how to give the enemy a certain ‘value’ of health. Like 1000 health, have a weapon that causes 15 damages, and subtract 15 from 1000. I get the basics, but I don’t get how to give the enemy 1000 health, and connect that with a health bar…
sorry if it’s confusing…