This is a great topic, 'cause no matter where you are or how old you are, there will always be some "smart" person who thinks they’re a superhero, and it’s easy for a small insect sting to scare you more than you’d expect.
Your friend is very lucky to ask you because you covered the topic quite well; I don’t even think Google explains it this well. Basic knowledge of first aid is always useful; it’s something that should be mandatory in schools.
In my case , I have some first aid kits at home, but that’s because I’m fortunate to work in a hospital; otherwise, it can be quite complicated here. Besides that, the healthcare system is so messed up that I prefer to treat my family at home. For me, it’s an important topic, knowing that almost anything can be deadly 😕