LM386 as the preamp and audio power amp. **broken link removed** to see how to set the gain of the LM386 to the higher gain which will be required to amplify the rather puny output of the electret. You will also have to "bias" the electret to get it to work (which the 386 doesn't do for you).
I think you will have acoustic feedback howling because the microphone will hear the speaker and the sound will go around and around.
Turn down the volume control and point the mic and speaker in opposite directions fairly far apart (or in separate rooms) to avoid the feedback.
Then talk loudly very close to the mic.