What software you using Tom, i use Elements 10, not into photo mechanic as it does all i ever need it to
In Elements, open your image and select, File/File Info
You will be greeted with a screen like in the photo below, caption by entering in the "DESCRIPTION" section something which describes the photo, ie,
Darren Woods slides over in the corner for the third of his 4 tries to secure victory for Thatto Heath in their play off game against Leigh Miners
For your first game this is really the only info Dave has requested so in theory all thats needed, i would fill in al, the other fields along the lines like ive done.
You dont need to do this to every single photo, once completed for one photo you can export an XMP file with all the data on it, then import it into other photos, you can create an action to automatically add it to every single photo.
To create the XMP file, look at the screenshot, at the bottom theres a drop down bos which sats IMPORT, click and select Export, this will ask you to save the current data on your hard drive, save to your desktop, open up next photo, go to File/File info and select import, browse to the XMP file and import it, everything will then be saved to this photo, only thing you then need to alter is to write a new caption for this photo
Ive altered the contact details in mine for privacy, if working freelance then also add payment/bank details