"Put on" means to dress yourself in clothing, so you put on your socks. We can also separate that phrasal verb, "you put your socks on." The opposite is to take off -- you take your socks off (ie remove clothing). "Take off" can also refer to an aircraft leaving the ground, but the meaning is obvious in context. There are many phrasal verbs with "put" and "take."

You use except to introduce the only things, situations, people, or ideas that a statement does not apply to. All of his body relaxed except his right hand... Travelling was impossible, except in the cool of the morning. You use except for before something that prevents a statement from being completely true. The classrooms were silent, except for the scratching of pens on paper... I had absolutely no friends except for Tom.

That's not good, Its not good to say that you want to say: I'm not wearing anything except socks. It means your naked

Both are right. The 'for' is optional.