Big mistake: you tried to turn it on knowing that it had “moisture and shit”.
If you feel confident doing it yourself remove the battery and check how deep the moisture you mentioned went. Try drying out with an hair drier but gently and from a distance. Let it dry at least 24 hours.
Or take it to a repair shop.
And get a new, water resistant bag, the old one proved to be useless in the rain
.
What model? You may be better off replacing the whole keyboard.