The good thing about Photoshop Elements is that it comes with lots of effects that you can apply at the click of a button.
Before you apply these, it’s worth visualising your intended final result and laying the foundations. Using the Quick Selection tool select a part of the image you want to keep in colour.
Use the tool’s options to add bits you’ve missed and subtract bits you’ve clicked on by accident. Invert the selection using Cmd/Ctrl+I.
This will select the entire background instead. Copy and paste the background onto a new layer. Using Enhance>Adjust Color>Remove Color, turn the background black and white.
Add some movement using Filter>Blur>Motion Blur. Apply a High Key effect in Guided mode and a white vignette with the Intensity set to maximum.
In Quick mode you can add some interesting colour adjustments with the Balance tool, adjusting the Temperature and Tint to get an array of results from moody blues to warm sepias.