Some things that really stood out for me, and to be clear this coved seizures, allergies (epipens) and legal issues as well.
You really have to press hard on the person you're doing CPR on. You're going to break ribs and the sternum. If you're not, They wont have a chance to come back from it. You have to be mentally prepared for that!
Using an Automatic Defibrillator sounds easy, its telling you what to do, hook up the pads and do it quickly and efficiently! Time matters, and is the main thing you're up against.
An adult has about 8 minutes of oxygen available while doing CPR. Time is your enemy. I did compressions for 2 minutes and was covered in sweat in a fairly cold room. Our instructor Melissa had a friend who had to keep up compressions for 45 minutes. I was wiped out in 2 minutes. I would be able to go longer, but it might not be enough.
With CPR there is the good Samaritan law. No matter the outcome, the person lives or dies you can't be prosecuted, in WA at least.
The same is not true with other aspects of first aid like injections with an EpiPen! There are many types / brands of EpiPens too. And a nasal one, versus the ones you stick in the person's thigh. When the shit is happening, people have the pen upside down and end up stabbing their hand with the needle. Time is not your friend or more importantly for the person in distress.
After you've placed the AD pads on a person you are not allowed to remove them! Only the paramedics are legally allowed to do so. And if you do remove them, they wouldn't stick to the chest and side again anyways.
So I learned a ton and have it in the arsenal. Will it save someone in distress, maybe but at least there's a better chance of me accomplishing it.
Ill probably think of more later and add more info. I took the class in Redmond and it was $44. I now have cards in my wallet for the certification.
Ill post the name of the place later, just can't recall it off the top of my head atm.