I'm a nutritional herbologist and just wanted to clear up the protein and calcium issue for many who think you won't get what you need. There is more protein per calorie in broccoli than in a steak and it is packed with assimible organic calcium. Other vegetables are very similar in nature. Getting these two items from plant based foods makes it easier on the body to assimilate and use them because of the form they come in and the fact that they come with all the other nutrients necessary for the process of assimilation and in the end the body doesn't end up with unused product as it would with animals foods.
As long as you make sure you are switching to a plant based diet and keeping the foods you eat as close to the original/fresh state you will do fine by eating a small variety of foods. If you eat what can be grown locally that is variety enough to give your bodies the nutrition you need without having to add supplements of any kind, but you don't need to limit yourself to a local variety. Stay away from soy replacements/replicas for filling in for what you take out. Making this kind of change requires a change in lifestyle, but one that will be for the betterment of your body.
We are not vegan, or even vegetarian, in our home, but keep our diet to a 90% fresh plant-based diet. Making this change came a little at a time. We found many recipes and books on the internet. You could try looking there for help in the food preparation area. As far as going out to eat, you will find there aren't that many options. In fact, that is where the other 10% of our diet is. We usually eat at Asian restaurants as they have a vegetable based diet that comes from their heritage. When we are invited to eat at others homes we would be gracious and eat what they prepared without the expectation that they prepare food according to our nutritional preferences and expected our children to do the same. Forcing others to adhere to your choices will only light fires, but be gracious and set a good example and others will eventually follow in your footsteps when they see how much your health improves.
If we invite people to our house for meals, we prepare our favorite dishes and have received the same courtesy from them as we have shown in their homes. It's hard to not enthusiastically share something with those you love what you know to be a great and beneficial thing, but the best way to do that is with respect. This I say from experience. If you occasionally eat the less than healthy foods your body will be able to cleanse itself as you mostly consume good foods. I would advise you to not worry about the occasional group/party eating and enjoy what is served and the company you keep, then return to your healthy lifestyle in your own home. If your children, while they are very small, won't eat what is there then take something for them, but as they get older (past the toddler stage) it could be considered by others to be rude if you take a meal for your family when you have been kindly invited to join others for a special meal.
As you learn what you like to prepare you will learn what tools you need as well as what spices/herbs, vinegars and oils you like to use. I use many more different flavors now than I ever did before we made our dietary changes. I would suggest learning how to pair flavors of foods and spices. A good book for this is "The Flavor Bible" by Karen Page and Andrew Dornenburg. I have found this to be the most helpful for me as I learn to make my own dishes from fresh plant-based foods. You may also want to look for a book on basic cooking tips if you don't have much experience in creating your own meals or changing recipes to be vegan. I have found that teaching myself to cook without recipes to be a challenge, but more rewarding.
Sorry for the lengthy post. Good luck. Please feel free to drop me a note if you have any questions you feel I could answer.