Mandatory calorie labelling isn’t legally in force in Scotland (yet), but lots of the big chains like Wagamamas (mentioned above), McDonalds etc. will display a value. This is an average for a ‘typical’ portion, so won’t be bang on what you’re eating but will usually be close enough if you’re tracking on MyFitnessPal etc.
Good for you for trying to make some changes, diet is the hardest part I find!