An amplifier (amp for short) is commonly used in conjunction with musical instruments, such as electric guitars and keyboards, although it is possible to hook up other devices to the speaker, including a microphone. However, hooking up the microphone does require you to use an adaptor as the signal coming from the microphone uses an XLR cable while the amp accepts 1/4-inch connections.
Insert the XLR to 1/4-inch cable into the XLR connection port on the bottom of the microphone.
Plug the free 1/4-inch cable into the 1/4-inch end of the adaptor.
Connect the available end of the 1/4-inch cable into the "Line-In" port on the front of the amplifier.
Power on the microphone and the amp, then talk into the microphone. The amplifier will produce the audio from the connected microphone.