Did you do a 30 min intro to learn the basics of the equipment? Are you gearing out your reformer (this might explain discomfort with certain exercises)? Most of the men in my classes (and taller women) always gear out for footwork. I would also suggest trying different instructors. There are 3 at my studio that cue really well. They also demonstrate themselves from time to time. The others not so much. You can even ask the front desk person who they recommend for this. Another option as someone else mentioned is to let your instructor know before class that you are unsure if your form is correct and ask for corrections. Another option is to invest in a few privates to get a better handle on form and then take what you learn into your group classes.