Know I’m not Loki, but I have taken a few basic first aid courses. Here’s my two cents on the matter:
First and foremost, you need to see if the area around the patient is safe. This is absolutely vital, as not doing so can cause you to become a patient, and two injured people are a lot more difficult for anyone to handle than just one. If there’s anything that is making the environment unsafe, as if and how you can deal with it.
Don’t mess with things like downed power lines, fires, deep waters, or anything of the sort. For lesser electrical shocks caused by, say, a frayed wire, remove that wire from the victim via a non-conductive object. Anything made of metal will cause you to be shocked—ideally you’ll want to stand on something too while moving the wire with a wooden object.
Now, call 911. Tell them about any hazards you’ve spotted. Alternatively, single out someone in a nearby crowd to do so. And I do mean single out, point at them, and give them specifically instructions to do so. The Bystander Effect is real, and people may not listen if thinking “oh, someone else will do it”. Also ask if anyone in the group has medical knowledge.
What I’ve just told you? More important than the rest. Getting aid and ensuring that you also don’t become a casualty can be more vital than actually doing any medical practice yourself. However, in the event that such is needed…
Next, if the environment is now safe, don’t move the patient, and begin to apply basic aid. I’ll list what to do depending on the wound below—
Minor Cuts. Gently rinse the area with water. Apply clean cloths directly to the bleeding area, and secure them with further cloths.
Serious Cuts. Similar premise to minor ones, but keep applying bandages if one gets soaked through. Don’t try to replace them, just put more on.
Impaled Objects. DO NOT REMOVE THE OBJECT. Whether it be knives, glass, splinters—whatever, just keep them in for someone more skilled to take out. Try and keep the patient from moving the injured body part.
Minor Burns. Honestly, most of what you can do about these is pain relief. Sunburns, scalds from hot water, and other things suck, but if you don’t seem any blisters or darkened flesh, it’s really not that bad.
Serious Burns. There’s a good chance some of the person’s clothing got seared to their skin. Again, if there’s no immediate threat, don’t try and move them. Have them lay down, and stay calm. Don’t try to remove any attached clothing.
Choking. If the person is able to speak at all, try to verbally encourage them to cough the object up. If that doesn’t work, or they can’t speak, get behind them, and place both arms around them, your hands at the front. Ball one hand into a fist, grasp it in the other, and shove it into their solar plexus.
(For choking, you probably don’t have time to call 911. Make sure it’s not being caused by anything in the air—if it is, RUN AWAY IMMEDIATELY. If not, get to it, on the double.)