Animate old photos

The 2.5D or Kid Stays in the Picture technique you are looking for involves separating foreground, background, and middle ground elements into different layers, doing the best you can to fill in the holes, then carefully arranging the layers in AE's 3D space and performing a subtle camera move. The more planes there are in the image the more difficult it is to do a believable camera move. 

I'm not trying to discourage you, but I am trying to give you a realistic expectation of how long this kind of work takes on average. Let's talk about the shot at 0:50:00. At the very least you'll have to separate these elements into different layers.

Then you will have to erase all of the details in the shot and fix the background wherever you want to have things moving. All of the cars, people, smoke. All of that needs to be gone and the background needs to be clean. For this shot. I'm guessing about 7 or 8 layers minimum and possibly several hours cloning. 

The next step is to either shoot actors to walk down the sidewalk on greenscreen matching the camera angle and distance from the camera so the perspective matches up or creating a virtual set and modeling and animating 3D characters. Generating the smoke is probably the easiest. Adding in footage of cars or making the cars in the scene appear to move is another task. 

That shot is about 4 seconds long and if I were to try and reproduce it exactly it could easily take me a week. If you haven't got that kind of time then you have to simplify.

You can kind of match perspective in Photoshop using Vanishing Point for some images, even this one, then you can make a little move with the camera to make it kind of look 3D. With some experience and practice, it might take you somewhere around 30 minutes to get a simple move, but making the cars move is going to take a lot of work. There are no automated tools that make this process a click and be done job.

Start out simple. Look up Kid Stays in the Picture or 2.5D animation. Most of the tutorials I found with a quick web search were pretty poor so I'm not going to give you any suggestions. If I find a really good one, I'll point it out.