How to make a photo blurry-looking?

it doesn't look completely focused, yet its not blurry. This photo was taken with a nikon d7000

These photos have such bad quality in terms of grain and blur. It was either taken on a very old film camera (possibly edited in the dark room), taken with HIGH iso and a shakey hand, or edited digitally after taking the photo. Just add grain and slight blur. Color correcting can also make your photo more vintage/Polaroid feeling.

What I think you are asking is how to achieve a "soft focus" effect. This cane be achieved either at the time the picture is taken or in post editing.
At picture taking time- use a light dispersion filter. These come in varying strengths but I have never used anything other than the weakest ones (a Cokin drop in filter one).It's a matter if taste and I find higher values too soft
In editing: in photoshop make a new layer then add a blur filter to the layer, there are different types of blur so experiment with them and the settings to find what you like
Another programme I use is DXOmark film pack- it takes your digital print and let's you apply the characteristics of traditional film types to it, emulating the grain and blur of different ISOs and film manufacturers

Professional and amateur photographers alike end up with a blurry picture on occasion. When that little bit of blur prevents a picture from looking like a masterpiece, you can sharpen the image using digital retouching software. While the software can't transform a complete blur into a crystal clear picture, it can sharpen edges and add clarity in just a few steps

1. Open the photo editing program on the computer and open or import the picture. Select the "Save As" option and save the picture as another document. This leaves the original photo untouched in case you need to revert to it later.

2. Close both copies and open the second version of the picture in Camera Raw. This program provides two important controls to help diminish the blur in the picture.

3. Mouse over the "Contrast" control and move the indicator a little toward the right to increase contrast. Mouse over the "Clarity" control and move the indicator a little toward the right to increase the clarity. Alternate between the two controls until you have eliminated as much of the blur as possible.

4. Click on the "Open Image" button near the bottom-right side of the page.

5. Duplicate the layer and then click on the "Filter" tab at the top of the page. Scroll down to the "Other" filter and select "High Pass Filter" from the list of options. This will scan the image for sharp color changes for clearer delineation. Adjust the threshold indicator to sharpen the color changes and reduce blur. Click "Okay" to apply the filter.

6. Click on the "Layers" tab and choose "Overlay" or "Hard Light" from the list of options and adjust the Opacity indicator until the image appears clear with more defined edges.