lucky for you, i was a speed/strength coach and have had experience working as leader for large groups of young kids to college age adults. you lucky s.o.b.
1. you never coached, doesnt matter. have a plan. day 1, 2, 3. do assessments of the big movements. bb bench, trap bar dead (great starter tool to see if they have a weak vmo which would limit both deads and squats as well as every other lower or upper body movement which requires knee stability), and squat if the deads are not complete garbage. if they are, steps ups and walking lunges.
2. never yell. convey your message with a nasty face. dont raise your voice. you lose all credibility. unless its a huge crowd and you need to get attention, never yell.
3. never, never, never curse. its a teachers role. teachers cant curse. i dont care what people say about coaches elsewhere. you can be fired for it if parents complain.
4. get a roster. seperate academic level (seniors, juniors, sophomores, freshman) and gender. go from here. after the assessments have specific levels and then differentiate your groups based on ability. boys and girls mix. strip the weight for the monster chicks and keep them with the boys. the girls are motivated by that and they are great cheerleaders creating a group dynamic based on the whole group versus individuals. i saw a 160 pound female gymnast flat bb press 185 for 23 reps. our program and mentality owned that girl. she became a disciple.
5. you set leveled routines but they arent specialized. novices should not do 5 x 5 due to joint instability alone not to mention lack of power exertion under strict control. make sure the tiers are labeled and out in the open like on posters for all to see. its a visual motivator, it will work. to get moved from one level to another, gotta be this good. ALSO, HAVE A RECORD HOLDERS BOARD FOR LIFTS AND WEIGHT CLASSES! JUST DO IT! LEAVE IT OUT IN THE OPEN ALWAYS AND ALWAYS MAKE REFERENCE TO IT. short and long term girls have to be labeled.
6. make friendly or avoid them. just do what youre being paid to do and avoid the noise.
7. you will not need specialty gear. make it an all raw group. make that a mantra. have chalk. do alot of abs and ditch the belts too.
good luck. remember you are the coach, not a friend. be kind, understanding, give clear/concise directions via tons of examples by you, be very firm. thats all.
and the most important piece -
dont ever put your hands on a kid. after a huge victory in public a hug is obvious. outside of that, i would not make hand slaps a regular reward. verbal praise.
my wife is a teacher and administration certified. i hear about this shit all the time.