I find these Prologues both interesting and puzzling. They were spoken by actors in the play, but not as any characters in the play. It looks to be basically a "here's the play - please like us" kind of statement.

But in light of the disastrous opening night, I thought these bits from the closing stanza of the first Prologue to be quite ironic:

"No spleen is here! I see no hoarded fury;—
I think I never faced a milder jury!"

"Thus, all respecting, he appeals to all,
And by the general voice will stand or fall."

Oh dear. No wonder Sheridan rewrote the Prologue. ;-)

I thought it interesting that he mentioned a character from the first Prologue in the second:

"Granted our cause, our suit and trial o’er,
The worthy serjeant need appear no more:
In pleasing I a different client choose,
He served the Poet—I would serve the Muse."

I also laughed when he mentioned the actors in the Prologue. But I'm not quite getting what Sheridan is talking about here in the last four lines:

"For here their favourite stands, whose brow severe
And sad, claims youth’s respect, and pity’s tear;
Who, when oppress’d by foes her worth creates,
Can point a poniard at the guilt she hates."