Mama always says...

Yeah, yeah, I know. Stupid is as stupid does. And I still don't really understand that quote, but whatev. I NEED HELP! I've got some stupid questions. Ok, so when you're reading chords for a song and they just have one capital letter above the word, that means to play that chord and not the note, right? And in tabs, when it just has one number on one line, you only play that one string? AND when you're playing like a C# (C sharp, right?) I know which note to hold down, but do you only strum that one string or do you strum all 6? Whoever can answer all these questions I would be very much grateful...even though I probly sound like an idiot.
~Mo