First - is it poetry? In this case, yes? How do I know? It sounds like a psalm. Such poetry must in translation preserve the internal pulse of the parallels - so step 1a is to figure out where these pulses are.
Figuring out the pulse: look at the music. It does it for you. The atnah is the rest point. The subdominant rest point occurs zero or one time in every verse. In verse 1 it is on יָלָ֑דָה - the symbol for it is the ^ under the ל. Put a new line at this point - then look for other disjunctive points in the music.
Step 1b - another consequence of poetry but also applicable to prose structure, is to observe the repeated words. I don't have this particular chapter in my database so I have shown a sample highlight with colour coding.
Step 1c - distinguish the words that are different - and do not use the same English gloss for them.
Here's the example of Isaiah 54:1
|רָנִּי עֲקָרָה לֹא יָלָדָה|
פִּצְחִי רִנָּה וְצַהֲלִי
מִבְּנֵי בְעוּלָה אָמַר יְהוָה
|Shout for joy, O barren who has not borne|
Erupt in a shout of joy and be bright,
she who has not writhed in birth
for many more are the children of the desolate
than the children of the married, says Yahweh.
Where are the parallels? line 1 is a / b, lines 2 and 3 are a' / b'. Lines 4 and 5 give a rationale for the invitation to shout for joy. The last two words identify the speaker, traditionally translated as the LORD. I think the name יהוה must behave as a proper name when translated, so I find the English traditional translations lacking. They cannot adequately distinguish in sound the Name yod-heh-vav-heh from the title Adon for Lord, husband etc.
So what does it mean and why is it here in this text in this chapter? I think it follows the stunning portrait in chapter 53 and celebrates the vindication of the suffering servant. Chapter 55 to come invites further participation - but maybe I am anticipating too much. Precision of interpretation is more difficult than translation.
The glosses above are consistent with the patterns developed in Seeing the Psalter. Isaiah is a lot like the Psalms. Writhing in birth, the same word as dancing, is a theme in the Psalms.