How to make my photos look like this

I have a nikon d3100 but I want know how to get this effect?

It's kind of an indie/vintage look

I see nothing in those images that indicate that the photographer did anything but use the cameras light meter and use light to create the look you like so much.

You can spend $700 for a camera, but you can't buy the skills you need to produce images they way you want. That takes time and learning to see what the light is doing before you press the shutter release

I think good expression, good camera angle and timing is very important but I want to tell you its all about skills.

You can to it by playing around with tones and saturation in Lightroom, but nothing in post processing can replicate the lighting in these photos.

You can't get those "effects" with a nikon d3100, because its a DSLR. Those were shot with an SLR, on film.

Point camera in random direction - press shutter.