Rest days are essential for your body to grow and recover. Take some time away from the gym today and enjoy the extra 25 minutes with your friends and family. Your body is changing even when you're not sweating it out in the gym, so don't worry about doing extra cardio!
Today is also a great day because it's a free day. That means you get to eat whatever you want. Now, that doesn't mean you get to pig out on fast food all day, but you can enjoy your favorite treats or meals. If you've been craving a burger, have one. Or, if you would like to have a slice of cake at your cousin's birthday party, do it.
You're learning how to eat for life, and that means you shouldn't ever feel deprived. As long as you've been eating nutritious, healthy food for the last six days, a free day will not undo any of your hard work.
It's also a great day to work on preparing your food for the rest of the week. If you're accustomed to going out to lunch every day, use some of your time today to precook lunches, so you can bring them with you to work.