Broken legs are basic stuff, I think just about everyone can handle that. The injuries that freak out people are the ones that require immediate and proper care. That obviously includes heart attacks and strokes. The ones I try to educate others on are brachial and femoral artery breaches. You have just seconds to properly treat those injuries.
I had a good friend die while deer hunting near Socorro, NM. He was a party kind of guy, and was hunting with his good time buddies. One of them shot a deer, and while he was running down a hill to inspect his kill with the rifle over his shoulder, he slipped and almost fell. The gun discharged and struck my friend in the upper arm. It severed his brachial artery.
There were four other people in this group of idiots, and none of them were smart enough to apply a tourniquet to my friend's arm. They were miles from any help. He died on that hill, bled to death while the others stood around and watched it happen. Many people are scared to apply a tourniquet to an extremity. They have heard claims that an improperly applied tourniquet will result in the loss of the limb. They don't understand that losing a limb is preferable to bleeding out. My friend died almost 35 years ago, and I'm still angry that it happened.
Are you prepared to intervene in a situation that is life or death? I've done it several times. I have enough training and confidence to do it. I'm not bragging, I just want to point out that training gives you the confidence. Situations that require immediate action will arise in your life. Don't be the person that stands around and watches someone die.