Starting a Plant Based lifestyle there will be challenges, so you MUST be prepared. If you are one of the only ones on this journey in your family or group of friends, it is likely that the food menu will not fit your restrictions.
There are 2 options to help you stay on track-
1) Eat before you get there.
2) Pack a healthy variety of foods to bring with you.
Fruits, cut veggies, nuts, salad, sandwiches/wraps, smoothies and water are perfect to take. If you are going to a family reunion or friends house pack a full meal to warm up. Take condiments like vegan butter, sour cream, cheese and most store bought bacon bits are soy (accidentally vegan) for a restaurant engagement with limited options to dress a baked potato and steamed/saute veggies. Bring foil wrapped veggies or vegan burgers to a cookout to put on the grill and enjoy with friends. Always offer to bring a dish to birthday/holiday parties with enough to share.
Just because your family and friends don't support your new healthy life style doesn't mean they don't care or support you being healthy; it's that they don't know enough about what you are doing. The best way to gain support is to tell people why you are doing it and let them sample your food.
Congratulations on changing your eating and lifestyle! You made your transition on your own time and terms let your friends and family have that option too.