If the room is small and reverberant, and the noise has multiple sources, position the microphone to reject the undesired sound. Pickup of unwanted sounds is inevitable. You can reduce these to an insignificant level by placement and some equalization, which is an electronic process which renders the wanted sound louder, and the unwanted sounds softer. Planning the recording event and predetermining microphone choice can minimize unwanted sounds. Feedback is always a problem in live situations.
Directional microphones are always the best choice.
Shotguns have a narrow pattern and a strong off axis, making them very sensative to movement when used to follow the action being recorded. When multiple microphones are required, using the same models and patterns should be acceptable. Now turn off the microphone that is on the stand. Place the handheld microphone about three inches from the mount. Set the level for this microphone to read about six decibals on the VU meter.