I have about 50 photos that I need to crop to 3.75 in x 2,75 in, 300 dpi. Is there a way to do this without entering the dimensions and dpi for every photo? PSE 2020 Windows 10
Go to File menu>Process multiple files
In the dialog you can enter the dimensions
Be sure to check "Constrain Proportions"
Place the photofiles in a source folder and make the destination folder a different one, so as not to overwrite the originals.
I would practice with a few dummy files to be sure that your setup is ok.
I'm assuming that you want to customize where the crop takes place. If that is the case, and you don't want to have random crops of your photos, you can enter the dimensions in the crop tool, and it should remain sticky and be applied for each new photo that you open and crop. The custom dimensions will be lost if you change back to another aspect ratio.