Obviously, if you haven't completed any of the campaigns or eye of the north, do that first... but then..
The two main things I'd do, coming back, is work on your hall of monuments (and you don't need to focus on one character, since everything you dedicate in HoM counts as account wide), and work on the Guild Wars Beyond content, which is the War in Kryta, and Hearts of the North, and soon Winds of Change and eventually an Elonian Guild Wars beyond package involving Palawa Joko? (not sure about that one).
You have Eye of the North right? If not, I guess none of this matters.. but it could be a good tour for anyone else in your situation that DOES have Eye of the North. Anyway through EotN you'll have your account linked to your future GW2 account.
So.. you have all the campaigns, and Eye of the North, your accounts are linked, and you've beaten all the campaigns... what then? First I'd suggest the Guild Wars Beyond Content, War in Kryta, and Hearts in the North. I think because it'll help you in the Hall of Monuments building, as Guild Wars Beyond content will get you Oppressor Weapons which you can dedicate for your valor monument, and will also give the chance at some hero armor items (via Keiran's scavenger hunt), and some rare minis (via drops from Peacekeepers/White Mantle, or via Royal Gifts) which can earn some more HoM points.
After that, things you can look to do for your HoM... now, try to earn most of these rather than just buying them out of Kamadan, as you'll see later, this will take you through quite a bit of the content Guild Wars has to offer.
Get 1 Vabbian Armor set on any character, 1 Obsidian (Fissure of Woe) armor set, 1 elite Kurzick or Luxon armor set (4 points)
Along with those oppressor weapons from War In Kryta, get at least 1 destroyer weapon, and 1 tormented weapon. (4 points)
Since you're coming back after a long time, you probably have minis coming out the ears now, you might sell some, but try to hold on to at least 1 gold and 1 green mini if you have them. If you don't get a green mini, get a black moa chick mini pet (actually do that anyway if you never have), but dedicate that 1 gold, 1 green. (3 points)
Make a new perma pre-searing character. It doesn't require death leveling now because of the new added vanguard quests. You can only do 1 a day, and I find that between the quest reward xp (1000) and mob kill exp (about 1000 a day unless you repeatedly farm it then it's obviously higher) it takes about a month of doing that to get your character to 20 for Legendary Defender of Ascalon.
Go work on a pvp title, any pvp title, gladiator from random arena, try the codex arena (that might be new since the last time you played. it's a "sealed deck" based team arena, not really my favorite, but it's interesting), at least try all the different arenas since there's account based quests for them with strongbox rewards to give you a taste. With this, the LDoA statue, and the statues for having completed all 3 campaigns, you'll have bare minimum 5 honor monument statues (11 points)
Acquire some hero armor for at least 1 hero, or dedicate MOX. Then get either a black moa, black widow, or imperial phoenix pet, and dedicate that (My vote is for the black widow since it gets you in Underworld). Then just get any random pet, and level it to 20 (you can use the Zaishen Menagerie to do this fast if you want, spending balthazar faction or zaishen coins (not sure if the Menagerie is new since you came back, but it could be)), dedicate that. (3 points, possibly 5 points if you get more hero statues or get the other 2 rare pets (which I'd do anyway))
That adds up to 27 points, you almost have enough to have all the items you can get from your HoM in GW2. After that, it's just more stuff, get some more minis, more hero statues, more dedicatable weapons, more elite armor, more titles/statues to get your 30+, and then you can keep going for some titles in GW2 if you want.
This isn't the most efficient way to do it, I'm sure people do Speedclears to make money to buy most the points, and speedbook for the max titles.. but
Look at it this way. When you're done doing it that way, you will have gone through all campaigns, EotN, Presearing Ascalon to LDoA, UW, Fissure of Woe, Domain of Anguish, Sorrow's Furnace, all the Guild Wars Beyond content, etc.
Oh, and since your timing is good, hit up the boardwalk and do some rollerbeetle racing
