I have recently finished my MS in biology and will be beginning in a PhD program this upcoming semester. I was recently offered an adjunct position at a community college to teach a summer course. It is an 8-week course requiring 8 contact hours per week (4 lecture and 4 lab). I have read/been informed that it is reasonable to expect 2-4 hours of prep work per hour of class time, considering the course is slightly outside of my area of focus and it would be my first-time teaching (outside of guest lecturing and tutoring). When accounting for the time needed to grade, respond to emails, etc., I am worried this single course could turn into a full time obligation (i.e., ~40 hours a week).
I am already working part-time as a research assistant for the university and am working on drafting a manuscript from my thesis work to submit for publication at the end of this summer. I would also like to spend some time with friends and family prior to starting my PhD, as I will be moving ~7000 km.
In the past, I have been advised by professors/researchers to make sure I don't take on too much simultaneously and to rather focus on the top few priorities. I have a tendency to spread myself a bit thin at times.
I am worried that by accepting this position I might be doing just that. I don't want to begin my PhD feeling like I have already been burning myself on both ends for 2-months prior. However, I am equally worried that by turning down the position I will be missing out on 1) an opportunity to grow as an academic by learning and teaching a course in my field that is outside of my usual comfort zone and 2) a strong CV builder.
My questions are:
-Is it reasonable to expect a demanding course to take 2-4 hours of prep time per 1 hour of class/lab time for a first-time instructor?
-Would passing on such an opportunity likely limit my growth as an academic/student or job prospects following the completion of my graduate studies?
-How much teaching experience will be expected upon completion of my PhD (or how much would 'extra' teaching stand out)? In other words, is this such a good opportunity that I would be 'silly' for letting it pass?
(For more context, I am interested in a career in research and plan to apply to R1 or R2 universities but would like to keep the option to work for other types of universities open. I will be a TA for at least 1 year during my PhD.)