Identify what is being selected
On a selectorised machine, a pin or another selector determines which part of the stack is engaged. Have staff show you how it should be inserted and checked on that particular model. Do not move the selector while the stack is in motion, and keep fingers away from spaces between moving plates.
Read the unit beside the numbers. A machine may display kilograms, pounds, both or a numbered scale. Some have additional small increments controlled separately. Ask what each control does rather than assuming the largest printed figure describes everything that is selected.
The purpose of this introduction is operating the equipment, not deciding what resistance you should use. That choice belongs with the instruction or programme appropriate to you. Another person's setting, or the position the selector happens to occupy, is not a recommendation.
Compare like with like
If you keep training notes, include the machine identity and the displayed setting. Different equipment designs and mechanisms can make a number on one station unlike the same number on another. Treat a change of machine as a new reference rather than proof that you have suddenly become stronger or weaker.
Even within the same gym, two stations with the same exercise name may not be identical. One may have a different movement arrangement or an extra adjustment. Ask staff whether they are the same model before combining their records. Your notes should describe what you did, not smooth over differences that could explain the result.
Avoid adding loose objects, unofficial pins or extra plates to a stack. If the available increments are not suitable for the work you have been taught, speak with the instructor about the options. Altering a machine to produce an in-between number is not an ordinary member adjustment.
A selector that will not fully engage, a missing pin or a stack that does not settle as expected needs staff attention. Stop using the equipment and identify the machine clearly when reporting it. Do not borrow an apparently similar part from another station to keep the session moving.
When you finish, follow the gym's instruction for leaving the setting and clean the contact surfaces. Keep bottles and belongings away from the stack area. The printed figures become useful once you know what the controls represent and how to record them consistently; until then, they are labels on a machine rather than a score to pursue.