I do not know if one or more of these videos show the best method for the instrument you have and for the machine/structure situation, but they are a good starting point:
Learn about Operating Deflection Shape Vibration Test
Search: ods vibration test video
https://www.bing.com/search?q=ods%20vibration%20te...
Learn about Impact Vibration Test for Natural Frequencies and Vibration Modes
Search: impact vibration test video
https://www.bing.com/search?q=impact%20vibration%2...
Walt (not a Beginner)