MS word is hardly great tool for images. I personally like Irfanview since it's free,fast, opens tons of image formats. It's not most powerful or particularly easy to use. Still it's fairly easy to use for your ask, crop/resize and print image as set size.
IrfanView ... one of the most popular viewers worldwide.
www.irfanview.com
You should be able to select card stock on walmart photo site, thought I never tried them myself.
p.s: still free, but more robust image editing tool is Paint.net if you interested in that sort of stuff:
Paint.NET is free image and photo editing software for computers that run Windows.
www.getpaint.net