The majority of effort for emergency preparedness is repetition so you don’t have to think about it. Understanding is good too, but in a lot of cases you shouldn’t be taking action based on speed if you don’t know the right thing.
For example, it is generally better to just make sure someone having a seizure has room and isn’t going to fall off something. Things like sticking stuff in their mouth like in the movies is a terrible idea that makes the situation worse, so not acting is actually better than acting most of the time in the case of seizures.
As a counterexample choking requires immediate and correct actions. Some things will expel the object and others will get it stuck in a harder to expel location, so bboth time and foreknowledge is important.
All you can do is learn about the right things to do, such as taking a first aid class, and practicing them so you don’t need to think about what to do.