Put it in it's logical place. If you try to force it into a spot that it doesn't really fit then you run the risk of it seeming contrived. My advice is to write the story until you write the words THE END. Then go back and rewrite whatever needs to be rewritten. Your main goal should be to complete the storyline, and then go back and edit as much as you need to. Remember, this is only the first draft, and it might go through several drafts before it's as perfect as you're gonna get it. I stress completing the storyline because most people who try to write novels will never finish. It's not as easy as they think and they get caught up in editing and trying to make it perfect on it's first go-around. Don't do that or you'll become frustrated and might end up quitting.
When writing you should introduce some kind of conflict or tension within the opening paragraphs. It doesn't have to be an action scene or the main action. I certainly don't expect the main action to unfold within the first chapter. You can always give the reader a hint of what's to come. For my sci-fi story about alien abduction, I introduce the conflict by having a child disappear out of thin air and then having my character seeing a dark figure running toward the woods, but he's not sure what the figure is and dismisses it. That's the conflict I've introduced in the first two or three pages. I don't begin to unfold the main plot until the very end of the first chapter. But, conflict and tension can be anything, including an argument between your characters or having a character loose something important. Re-read the first two chapters of your favorite books and see how they start off. See where the author inserts some minor conflict or tension - look for the things that make you want to keep reading. I'm currently reading Harry Potter, and I've read the first chapter, and the author has tension from the very beginning by having the characters worry about whether the Potters are in town. It also has tension by showing how angry the father is and how scared he is to tell his wife that he thinks the Potters are in town.
I also suggest you start reading some writing websites that will give you advice on how novels are written. http://www.writersdigest.com is a good place to start; it has lots of articles for aspiring authors.