Red Cross first aid course

Today I saw someone had some sort of attack in the middle of the street, no one knew what to do and everyone was staring, incluiding me. I dont want to feel useless again in a situation like that so i decided to do a first aid course, i saw that red course has some courses partially online but they are quite expensive for me. I also cannot find them pirated anywhere, if you know where to find the red cross or any other first aid course for free please let me know :)