Yum! I love sassafras tea. Grew up having it all the time but that's because I lived in the country and it was easily available.
It's tasty and the color of the water is a beautiful salmon color. Enjoy it. You were given something delicious.
If it is ground, all you need to do is to put it into a "bag" you can fashion out of a paper coffee filter or, if you have one, put it into a fine mesh metal tea ball. Steep in boiling water. I add some sugar when I make mine. Do what suits you since this is something new.
"As a girl I had zero interest in the stove." - Julia Child
This is real inspiration. Look what Julia became!