Well, you're trying to emphasize that it's NOT the right time for something, right? So I'd say pressure the 'no' parts of these phrases.

Its best to put the stress on NO, and its emphasizing that the present moment is inappropriate for things such as joy or sorrow. If instead you want to emphasize that there are too many other things to worry about other than joy or sorrow, you might say, "There's no TIME for joy (or sorrow)" with the emphasis on TIME.

As a native speaker, there is no difference between those 2 ways, or the 3rd way with emphasis on both words: 'There is NO TIME for ....." It is just the preference of the speaker to emphasize certain words.

Stress can be placed on any word that you personally want to emphasize. What is the word or words in the phrase that is really important to you personally? That is what you stress. THAT is what you stress. That IS what you stress. That is WHAT you stress. That is what YOU stress. That is what you STRESS. Each of these takes on its own particular nuanced meaning, chosen by you. :) Does that make sense?

'no time for' is repeated, the contrast is between JOY and SORROW, the stress should be on these rather than either of your alternatives.