How many instructors?
You may be fortunate and get the ideal one for you first time out. This is by no means certain. Consider that your learning style would be matched to a teaching style for best skills transfer. Remember when at school you might say something like "Sorry, I do not understand" and the teacher then says and does everything again in exactly the same way except perhaps louder and sarcasticly! No learning takes place - time to get another teacher with a different skill set that can explain or demonstrate in a different way. There is no one best way but there may be a one best way for yourself.
Generally you will learn different skills from diffferent people or perhaps just get a better understanding of the same skills by having another approach.
Main thing is get prepared and enjoy soaking up what you can from all you can...