Your being hired to do a job, and unless you’re flying the clients equipment, the expectation is that you are skilled at what you do and know your gear inside out. The client is typically buying the complete service to collect the photos/video, and aren’t there to support your efforts in terms of the process beyond what they want shot.
Showing up on site and not knowing how to solve simple issues, or optimize camera settings can quickly drop the confidence the client has in you.
You don’t want to be trying to figure out how to set the ISO or change the frame rate on your camera in front of the client for example, eating up time and coming off as unprepared. Things like this should come natural and be second nature to you. Take the time to learn the gear inside out before taking on a job.
The client may have specific preferences for settings, and you should take them into account, and make sure the camera and gear is setup the way they have requested. If the requests are of concern in terms of the quality of the imagery they may produce be sure to raise concerns and give suggestions, but to do so knowledgeably means known your gear so you can speak to it with authority and confidence.
There are exceptions, where the client may want to setup and manage the camera for example, but in most cases they will be looking to you for all elements of the serial portions of the shoot.