What to do as a fresh lvl 40?

[Xalon]

Level 40 - lots of options.

1 - make sure you get your reknown to match your level rank. Do this by joining RVR and certain RVR quests.
2 - go to LOTD and kick butt.
3 - run endgame dungeons of which most are high level, many giving you great armor sets
4 - complete the thousands of quests across T1-4 in all three pairings (ignore if only in this for PVP)
5 - run scenarios (all level 40 players fight level 40 players in scenarios)
6 - get full influence across all chapters in your own pairing or all three

Just a few things in no particular order - stuff I will definitely do when I hit 40 again.

Good Luck! Don't rush! Enjoy all there is and have fun!

[Xalon]

What I try to do is this:
Complete all PQs for my pairing
Get full influence for my pairing
Complete all quests in my character's racial pairing.
Complete all RvR quests (includes every scout, keep cap, etc quest)
Explore all the zones in pairing to find the quests that aren't given in an obvious way (click on bodies, click on npcs on roads, etc)
Complete all the quests in LOTD so only daily quests remain.
Unlock ToK achievements however is possible.
Collect sets to get all the Wards I can.
Run every Lair in my pairing at least once.
Run every dungeon in my pairing plus Altdorf
Run every raid at least once.

If you do this, you can have a mostly unique experience for 6 different characters, one from each race. There is 6 campaigns for PVE and the shared War campaign for RvR. The coolest thing is that while going back to T1 for RvR will turn you into a chicken, going back to any lower level zone is perfectly fine. So can get everything done.

RvR is always fun, but PvE, especially with the -75%XP scrolls, is great fun. The PVE campaigns are probably the most underrated part of WAR/RoR. It blew my mind when I first played during live.

I'm sure there is more to do, like collect all armor sets and weapons at cr/rr 40+ or dueling every race and class.

Have fun! Sorry for late post