I applaud both you and your husband for deciding to lose weight. The activities you choose can be fun for both of you if you don't overdo it. It will take a while to lose that much weight, so set smaller goals at first to gain a sense of satisfaction. I should say also that unless you husband is very muscular or very tall, then his goal of 215 still sounds heavy.
First, look up a height/weight calculator online to determine the desired weight for your age and gender.
Make a chart to record your exercise and weight, get a good scale so you can monitor the loss. If you don't now cook most of your own meals, you should get some low-fat cookbooks and start. It might be a good idea to join a fitness center, some offer 24/7 hours to fit anyone's schedule. If you opt out of a gym, look for other ways to exercise, a daily walk or jog, biking, swimming, tennis etc. Start with 30 minutes every other day, and work toward 1 hour at least every other day (or 5 per week if possible). Activity should be brisk enough to elevate your heart rate to 70% of maximum ...you can find your maximum heart rate online also.
When cooking, this can be a fun activity for both of you. Eat fresh fruit/vegetables, lean protein, and high fiber carbohydrates....add lots of salad and green vegetables to your diet...low cal and full of vitamins. Be sure to eat three meals daily, a couple of fresh fruit or nut snacks also. A pound of weight loss is equal to cutting 500 calories per day for 7 days. So expect about 1-2 pounds of loss per week. Crash dieting doesn't work over the long haul, and it can't be maintained, you want to reteach yourself how to eat.
Cut out junk food, soda and pastry. You can eat anything but steaming, broiling, grilling are healthier. Control your portions. Buy a few measuring spoons in large sizes so you can measure out the correct amount until you get used to it. Buy a calorie counting book so you can monitor the amount you eat. You can also find informtation online about how many calories you should consume. Make small changes at first, so you don't feel deprived and reward yourselves as you lose weight with a dinner out (just watch the food you eat), a new outfit, mini-vacation etc.