It's my second day of learning on my acoustic guitar and I already got stuck on something. I know all the major chords and they sound ok (as they can sound in the second day :) ), but I have a problem with single notes. How can you make them sound clearly? Do I have to push harder on the frets (then I don't hear anything), or less (it still doesn't sound right)? Or do I have to play harder with my right hand?

Sorry if this has been posted somewhere I couldn't find it, and nothing of this type is written in any guitar trainer I've read...