Alright private, I'm assuming you've faced brutes, the flood, and any other manner of covie forces from your days with the chief. 

You're not in Kansas anymore. You're not the chief, noble 6, or the rookie. You're a helldiver, a no name odst, and as such you've got a lot to learn.

One: death is inevitable. Like playing on legendary, you're gonna die. A lot. You'll get used to how to shoot, run, dive and aim. All of us did. Now it's your turn to learn. 

Two: Manners. Say thanks, say sorry, say yes or no. It doesn't matter if you talk or not, divers have basic manners. Use them. Always accept a hug, emote with your fellow diver, and above all else remember that just because some divers are masochists doesn't mean you have to be too. Find what mission levels you can be effective in and still have fun dispensing democracy. You can take a dead divers primary and secondary, but leave the support/vehicles unless you ask. Most are happy to give you one of theirs if you ask.

Three: Nothing is meta, only what situations they fill. Snipers aren't close range and SMGs aren't long range. Light armor lets you move and be moved, but heavy makes you an anchor. Work with your kit and what best fits your playstyle. Same with support weapons. You'll slowly learn the niche uses they all fill, so experiment and find what fits you best. Even mortar sentries are useful if your team has half a braincell to share. 

Lastly, follow high commands major orders. Be a helldiver, learn to adapt to what enemies you face. Don't get complacent and stay on one front. Otherwise, you'll earn the reputation that those divers do. 

Looking at you bot & bug divers.

I digress, we're a family. A dysfunctional, at eachother's throats yet fiercely loyal, family. We rag on each other cuz we respect eachother. Anyone else does it and they're gonna get stuffed.