If this is your first play, have you considered joining a writers group?
If you live in WA, then the KSP scriptwriters group meets at 10.00am on the first Sunday of each month.
At 11 Old York Rd, Greenmount.
At the very least, they will give your play a reading and then supply constructive feedback.
Please be sure to check the FAQs:
Looking for work?
Agents and agencies
Finding an agent
Where are the auditions?