Tintin movie...what happened next?

Even though it's been several years since I read the stories last (maybe I should get them from my mom's), I got somewhat annoyed when I saw the movie that they mixed up several stories , and I kind of lost track of which story they were in.

The full title of the movie is "The Adventures of Tintin: The Secret of the Unicorn", suggesting that it's mostly based on "The secret of the Unicorn", but as far as I remember the ending is mostly the end of "Red Rackham's treasure", but the most of that was not included, so arguments could be made for the next to happen being both what happens in "Red Rackham's treasure" and in "The seven crystal balls" (the next comic book in the series).

If you decide to find the books and read them (and as Paulie_D I can recommend that), I highly recommend reading them in the right order. The danish translations (I'm danish, so that's what I originally learned about Tintin from) have a strange ordering and from wikipedia I can see that the english translations are also published out of order, but many things makes more sense when you read them in the original order.

Is there another clip/movie/anything that saws what happens next?

The movie was based on the based on three Hergé comic albums: The Crab with the Golden Claws (1941), The Secret of the Unicorn (1943), and Red Rackham's Treasure (1944)

A sequel has been planned for some time but has been stuck in "developement hell" for a while.

Latest news is (per Wikipedia):

On 19 November 2015, Polygon announced that the sequel is titled The Adventures of Tintin: Prisoners of the Sun and that it would be released in December 2016.

On 18 March 2016, Scout.co.nz announced that Jackson would be producing the sequel rather than direct, and that it would be released on 16 December. They also announced that a third Tintin film is in development, with Jackson serving as executive producer. Jamie Bell and Andy Serkis were reported to be reprising their roles in both the films, but Serkis stated later in the month that he did not know when the sequel was going to enter production, despite claiming that Jackson is still interested in making it.

Spielberg later announced that Jackson is still attached to directing the sequel, and that it would enter work once Jackson completed another Amblin Partners/Dreamworks production.

There are (I beleive) 24 official comic albums although they are very much a product of their time and have been the subject of some controversy due to their depiction of non-European characters and other issues.

The earliest stories in The Adventures of Tintin have been criticised for displaying racial stereotypes, animal cruelty, colonialist, violent, and even fascist leanings, including ethnocentric caricatured portrayals of non-Europeans.

While the Hergé Foundation has presented such criticism as naïveté and scholars of Hergé such as Harry Thompson have said that "Hergé did what he was told by the Abbé Wallez", Hergé himself felt that his background made it impossible to avoid prejudice, stating, "I was fed the prejudices of the bourgeois society that surrounded me."

That said, they are very much worth a read (IMO) if you can find them.