Which mountain bike skills do you need?
The most important one is self-assessment. Don’t do things which make you feel insecure. There is no (group) pressure and if you want to try obstacles more than once there is plenty of time for that.
Also before we start our tour I always know the technical mountain bike skills of each participant and adjust my route to those skills. I know the trails we ride and I will always warn participants about difficult passages and give advice when needed.