I know of this really cool website that tells you all about stuff like this, almost everything about growing pot you could want to know. I don't know if I should tell everyone where it is though???
Sorry... I had to say that. Here's one on topping... (and don't worry you don't need to read the whole thing)
https://www.rollitup.org/general-marijuana-growing/13820-fimming-topping-101-a.html
You could also search supercropping in the 'riu' search. Maybe a tag search, you'll see what I mean (i think).
https://www.rollitup.org/search.php
https://www.rollitup.org/tags/
I think topping is the easiest, becuase you just cut it and leave it. However topping and doing LST can have the same effect as a scrog with no screen, spreading the plant out for more buds and better light usage. Check this guys thread for that technique.... it's pretty cool, but might be too much work for the 6 plants you got. (again this is freaking long, you don't need to read the whole thing to get the training idea)
https://www.rollitup.org/grow-journals/181208-mammaths-stealth-cabinet-grow-journals.html
I have to say... I think it's great that you have all different strains, but I think it's really going to keep you on your toes. I have 5 of 1 and 1 of another and it always amazes me how different they are and how I have to treat them so differently. And both of mine are supposedly the same flower time and close in indica/sativa mix. It will be wild for you with a broader range.
You shouldn't worry or anything, just be ready for excitement. It's kinda like having 6 kids your first time around (that would be fun).
I'm so jealous of when you actually have everything harvested.... that is going to be the best buffet of strains ever.