Where to specify image dimensions?

Hi folks!
how’s going?
a little help for my little music blog

As I see on GT Metrix I have 4 images on the homepage without dimensions specified…

Where I have to specify image dimensions?
Which PHP file (i use wordpress)?
The issue is just on the home page and the images are:
https://musicanueva.es/wp-content/themes/bodega/images/icons/star-half.png (Dimensions: 14 x 14)
https://musicanueva.es/wp-content/themes/bodega/images/icons/star-off.png (Dimensions: 14 x 14)
https://musicanueva.es/wp-content/themes/bodega/images/icons/star-on.png (Dimensions: 14 x 14) (3 uses)
https://musicanueva.es/wp-content/uploads/M%C3%BAsica-Nueva-Logo.png (Dimensions: 182 x 88)

Thanks a lot!