In terms of exercise, find something you enjoy. I don't work full time, but with using public transport, I'm away from home for over 11hrs a day, so no exercise before or after, either. I try to go for a 20-30 minute walk during my lunch break - I only get a 30minute lunch, so I eat at my desk on the days that I walk.
I also did a Nordic Walking class last year, and found it a great form of exercise. It's also something that you can start of gently, and build up. You can walk by yourself or with a group. However, in years gone by, I swam, as a bit of a water baby. I also like to go paddling in my kayak in the warmer months.
In terms of diet, I don't think that there's any easy answers.
Take care