Just make sure you make notes or get them to jot down the settings & make sure you understand what they refer too.
You should get as a minimum for the fork & shock:
– Air pressure
– Rebound setting (how many clicks of the dial from fully anti-clockwise or clockwise)
I'd be tempted to get them to tell you what to do and you actually make the adjustments. That way you'll understand and get more for a feel of it, so you are more confident to do it in future. It can be quite daunting.
If you have a note of the base settings, then at least you can fiddle around with it and will be able to return to those settings if it feels wrong.
Probably worth wearing something close to your riding gear & taking your camelbak with it's usual fill along as well., so they can set it up for your riding weight (incl. kit).