Resizing an image to a very small size like 64x64 pixels inherently involves a loss of detail. However, there are techniques to minimize the "bad" look and preserve as much visual information as possible. Here's a breakdown of strategies:

1. Choosing the Right Resizing Algorithm:

Nearest Neighbor:
This is the fastest method, but it often produces blocky, pixelated results. Avoid it if quality is a concern.
Bilinear or Bicubic:
These algorithms smooth the image by averaging pixel values. Bicubic generally produces better results than bilinear, offering smoother transitions. These are generally the better options.
It is generally agreed that bicubic resizing algorithms offer smoother transitions than bilinear resizing algorithms. So when given the choice, it is usually better to use bicubic.
2. Image Preparation:

Simplify the Image:
If possible, simplify the image before resizing. Remove unnecessary details and focus on the essential elements.
High-Resolution Source:
Start with the highest resolution version of the image available. This provides more data for the resizing algorithm to work with.
3. Software Tools:

Professional Image Editors (Photoshop, GIMP):
These programs offer advanced resizing options and allow for manual adjustments.
They typically provide various interpolation methods (like bicubic) and sharpening tools.
Online Resizers:
Many online tools can resize images, but their quality varies. Look for those that offer bicubic resizing.
Here are some examples of sites that provide this service.
imResizer.com
watermarkly.com
Fotor.com
4. Post-Resizing Adjustments:

Sharpening:
After resizing, the image may appear blurry. Apply a subtle sharpening filter to enhance the edges.
Contrast and Brightness:
Adjusting the contrast and brightness can help improve the image's clarity.
Manual Pixel Editing:
For critical images, you may need to manually edit individual pixels to correct distortions or add detail. This is especially true for very small sizes like 64x64.
Key Considerations:

Content of the Image:
Some images, like simple icons or logos, resize better than complex photographs.
Purpose of the Image:
If the 64x64 image is for a small icon, a slight loss of detail may be acceptable.

Talk To Food Lion

"…without making it look bad?"

is the kicker…

Halving the resolution (which reduces the number of pixels available by a factor of four) is inevitably going to remove detail on anything more complex than a blob.

Within that, the PMC editor is not a full feature program; you will likely have better luck loading the png into something more powerful where you can try different interpolation algorthms for the scaling, and various filters on the result to sharpen (or otherwise enchance) the smaller version. [​My preference is GIMP - GNU Image Manipulation Program, but – like most of the high end programs – the learning curve is steep enough it makes sense only if one has a continuing use for the program.]
No matter what you do, dropping the resolution by 2X is going to have a strong effect and will almost certainly take some 'hand pixel pushing" to produce a fair looking result — which simply cannot match the detail of the original.