Laptop just ran out, why?

I just played Sims and then my laptop simply went into sleep mode (it said: sleep mode is started). The laptop wasn't overheated either, so I made sure of that. Since the laptop is also very old, it must always be charged when you want to use it.

Strangely enough, the laptop went out immediately afterwards and even the small indicator that the laptop is charging is not lit.

What can it be and what can I do?

Is the laptop still on? Did you accidentally press the wrong key?

No, the laptop doesn't work anymore and I don't know what you can press wrong there, but as far as I know I didn't press anything that I usually press

I would plug in the laptop even if it does not show that it is charging and wait for a while. Then try to turn it on again