Work outs n diets

I’ve been on vacation for about a month now, still have 1 more week, and I have gained sooo much weight, I’m about 156 which is the most I’ve ever weighed. Usually I’m about 135. When I get home I SERIOUSLY need to start working out and go on a diet, I just don’t know where to start. I’ve never been on any kind of diet and I don’t really workout, I go on 2 walks a day with my dog and that’s about the only physical activity I get. I need some help on what work outs to do and what kind of meals to eat, I’ve been thinking about doing intermittent fasting, I’m just not sure what to eat. I would prefer to do work outs at home, going to the gym and working out in front of people is just not for me. Any suggestions would help :)