do mistakes actually ruin your brain permanently?

I think I read online that if you make common mistakes early on, they get like, permanently stuck in your brain and you can never fix them? Is that true? I'm so scared of practicing now lol. Also maybe I should just memorize place names for a trip instead of grammar? But wait, what if I say a word wrong and it sounds like a totally different word and people get mad? Idk I'm so lost.