Aerobics/barre before or after cardio? Also, when do you eat

SAC0O3

I am going to the gym and I have a 2.5hr window that I am able to work out (while my son is being watched in the nursery)

I want to do a work out class (skinny jeans barre, which is sort of like ballet?) it is an hour long. But I am unsure as to whether I should do 30 minute jog before or after (and 20 minutes leasurely walking). What order should I work out in?

Also, when should I eat? Before or after? And what is best to eat before and best to eat after? I keep reading all sorts of different things online and would like your opinions.