Mist
It is hard to answer what a typical night is like, it will depend a lot on what you enjoy doing, and where you're at character development wise.
I'll skip PvP, WvW and Raids since I don't do those and not familiar with the content all that much.
Character development:
Farming Hero Points to unlock the 2 elite specs(HoT and PoF), if you're interested in them. It doesn't really take long to be honest. HP in HoT and PoF give 10 HP each, the ones in HoT are hard to solo, some might not even be soloable at all. The ones in PoF are a lot easier to solo, but some of them require the mounts rank 3 abilities to be able to reach them.
Speaking of mounts, there is Masteries also to unlock for character development, they are account wide btw, where HP are character specific. There's 3 categories of Masteries, Tyria(original world), HoT and PoF(mounts and their abilities). Masteries if you're not familiar consist of 2 things...experience, and Mastery Points. You get experience for each category for doing stuff in that part of the world, you also unlock the Mastery Points in each region like HP, or via story, or achievements. This can be quite time consuming.
Tyria masteries are the least required, they afford you some quality of life and some bonuses but are not "needed". HoT masteries are required in HoT and Season 3 zones, there's a lot of them and the XP requirement is quite high to unlock them all. The only useful one outside of HoT is gliding and it's different ranks, but not required. PoF masteries are all mount related, they are required in PoF, and very useful in the rest of the world. XP requirement isn't that high, much easier to obtain than the HoT ones.
Last in the character progression is gearing up...and that's trivial to exotic which is honestly all you need unless you plan on raiding and pushing Fractals to very high level. If you want ascended, there is a lot of ways to acquire stuff, all of which is very time consuming, and/or costly.
Non Character Progression Stuff:
This is stuff doesn't really impact character development, and is really the bulk of GW2.
Dailies, doing 3 of the dailies will give you 2 Gold which is a very nice amount, especially considering the ease of doing them. You have 4 or 5 to chose from, doing any 3 will give you the 2 gold so you can generally focus on 3 things you enjoy as they are different activities.
World Bosses, and Meta events. This is pretty much self explanatory, you go kill world bosses and do events, there is almost always someone running all of them. These reward you in gear, money, XP(for masteries), karma, materials for crafting etc...
Achievements, there are tons of achievement in GW2, and some of them reward you with titles, gear, xp, money, etc...also for every 500 or so achievement points you earn you get a chest with some decent stuff in it. For example at 5000 achievement points you get 400 store gems and a choice of weapon skin.
World and Zone completion, you get some decent rewards for getting 100% exploration of a map, and 100% of the world(original game only). The most important is a chance at a Black Lion Key to open the stupid chest, which can contain some unique weapon skins, and useful stuff...but mostly garbage.
Fashion Wars, that's the nickname of Guild Wars, and it keeps TONS of people quite busy, essentially trying to unlock armor and weapon skins to achieve a certain look.
Fractals, this is the dungeon running of GW2. They are quite fun and fairly short. Can unlock skins, ascended gear, etc.
So what's a typical night like.
First my main character is in full ascended, and 100% world completion and has completed all the stories, and I have 190+ Mastery point which is not all, that's like 250 or so, but I am not getting the rest of HoT, or raiding...so I think I need 2 more ranks in Tyria legendary crafting(which I am not really interested in).
So for me it goes like this.
Dailies for my easy 2 gold.
Crafting my daily ascended stuff.(don't need them, but I still do them in case I want ascended on an alt, or eventually just sell the stuff. It's worth a lot.
Doing the Halloween dailies, for chance to unlock skins, and stuff.
Doing a few runs of the Halloween dungeon with Hekotat for a chance at unlocking some skins.
Switch to my Guardian alt and work on her story, still in the original game but I plan on doing all of it to PoF. And doing map completion of maps that the story sends me to. Also getting HP on her to unlock the HoT elite which she doesn't have, no rush though since I love the PoF one which I unlocked already.
We haven't in a while, but we ran a few fractals once in a while(2-3 at a time).
Work on random achievements.
The fun part of doing world/map completion on my alt is I have access to the mounts from PoF which makes thing faster and easier.
Like Faltigoth said, more often than not it's more a problem to decide what to do because there is so much, rather than trying to find things to do.
I've said this before though, GW2 more than any other game out there is something you play for the sake of playing it. Very little is required, and once you're in exotic and finished the story...there's no real progression to speak of. So people used to the usual progression of MMO like WoW where you constantly get better and better items all the time via new content usually get bored quite quickly. There is no power increase in HoT or PoF.
Hope that helps.