Hi,
All in all, the first episode this season is merely a pickup of all the stories so far, and in the next few chapters we will find which stories live or die.
In many ways, the opening gave in to try and help the audience see/find the many stories that otherwise might not have made too much sense on their own. Personally, like the previous seasons, I did not need to see a whole reason for it all on this episode other than the "delicious" take of Aria's on the episode, up to and including her telling her new friends ... "to kill a queen" ... that got all of them a big laugh! Best moment of the whole thing!
The whole thing makes a whole lot more sense if you get to watch it from the start. Since it is 6 seasons, and a good 60 hours ... you might have to look at things later, since the new ones are here, but watching the new stuff without knowing the background, is a bit of an empty story ... for my tastes.
If anything, watch all 10 episodes of the 6th Season, so you get a fairly good primer to the new season, although the story that follows ARIA goes all the way back to the very first SEASON of the show, and her involvement on what she does now. When we see her in that opening scene ... which had me going ... WHAT? ... until she pulled her mask off!
Some things in this episode. Jorah is still alive (hand in the jail cell), and my guess is that Samm might try and find a cure for him? The whole of Dany going up to the castle was overblown, and makes us think that she will be the Queen of the 7 kingdoms. Jon Snow is trying to sound like a great leader, not sure it will hold. Too many doubts around. Cersei looks kinda lost and alone, and it might be a hint that she will become even more fierce, though she has lost way too much along the way to be able to take it to a finish line. Little finger is still hoping to be a part of the story ... good luck! Sansa, is still a "stupid little girl" and her comments to Snow are petulant, even though she makes a good point ... but she misses on the bigger point of it all!
I'm hoping that the whole season is not wasted on one war or two ... the whole thing with the undead on the north is getting boring and pathetic ... and not necessary, though it makes a suggestion that Jon Snow and his folks can not possibly fight for anything ... else, other than the Winter enemies they already have.
Do make some time to watch the early stuff ... the first season is quite good all the way through. I do not have a special favorite of the 6 previous seasons, but do think that the mis-use of the Red Woman in the whole story (someone could have gained better insight into her history and abilities ... instead of wasting her on superstition!)
All in all ... a very good show.
Btw, do a search on the net for the characters for GoT ... and check out the listing and the quality ... almost all of the top ten, are top actors that have won a heck of a lot of accolades all over England, and it shows ... their show has outstanding acting all the way through it.