Answer:
I have two hands but cannot clap
You use a knife to slice my head. And weep beside me when I am dead.
I run through hills. I veer around mountains. I leap over rivers. And crawl through the forests. Step out your door to find me.
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.
Sleeping during the day, I hide away. Watchful through the night, I open at dawn's light. But only for the briefest time, do I shine. And then I hide away. And sleep through the day.
People take me on walks and I run and have fun. What am I?