A live table read is exhilarating for a writer... you finally hear peeps speaking your words! But, if you're like me, you might get caught up in that and being critical of the work itself will be last on your list. You'll simply be thrilled to hear people acting out (no matter how poorly or expertly) your words.

My advice? Get friends to read it for you first at your home so you can get that whole excitement out of your system. And because they will likely not be professional actors, you'll be more likely to spot areas in your script that need work. Once you've gotten a sense of what needs work and you address those needs, then I would go for a formal reading. You'll have popped your cherry by then and be less star-struck, less enamored of people reading your words... and hopefully you'll be more able to be critical of your own work as opposed to enjoying the moment.

As others have mentioned, you'll likely need people to double or triple up on characters. That said, 24 is an extreme reach, especially for a newbie playwright. Go through your script and try to eliminate the small parts that require just a line or two, and further combine other lesser characters in to just one. I try not to have more than five or six players in a play because as a non-name writer, theaters are less likely to put on plays with massive casts. It helps your odds.