What are the unwritten rules of Lacrosse?

I’m coaching my son’s U10 team and 8/9 of the boys have never played lacrosse. We recently had our first two games and it dawned on me that like other sports (Baseball for example) there are probably unwritten rules/norms/traditions of the game and I was curious what those were.

Example: Do you always keep the head down on the ground when just standing around? I see this a lot.

Basically, what’s some knowledge I can take from y’all and share with my players so they don’t feel like complete “noobs” on the field.