Hi. Nice to meet you.
Actually, most case, you can use both for every sentence.
Everything up above are ok, but へis more formal.
If I say, I'll go to the park
We don't usually, use へ for a casual communication.
Probably, only for writting and very polite situation, you might be using へ.
I'm sorry that I'm not good for explanation.
Hopefully, this will help.