I'm currently adapting a coping questionnaire which has been widely used in sports to be used with a different population (musicians), so I need to address its reliability and validity with this new population. I'm a novice in statistics therefore any advice will be very helpful.
The questionnaire has 39 items on a 5 point Likert scale (1=not at all; 5= very much). In sports population, EFA and CFA have shown a 10 first order factors and 3 second order factors. Since I'm unsure if in the new population (musicians) those 10 factors will be the same, I'm wondering how I should proceed to test validity and reliability. My questions are:
1.Should I calculate the Cronbach's $\alpha$ for every 10 first order factor from the original questionnaire in order to test internal consistency (and perhaps delete some items) and then proceed with a CFA? Or should I run an EFA with all 39 items?
Once those X first order factors have been established, will I just need to run a CFA to confirm (or not) that they load in a 3 (perhaps just 2) second order factors?
I'm collecting my responses to the questionnaire right at this time, and I'm expecting to get between 100-120 observations. Is this sample enough to perform those tests or would I need a larger one?
Thank you very much for your advice.