Hiya, and welcome!
Only eating one time a day isn't going to help. When your body doesn't have enough food, it starts turning to muscle, which you don't want. On top of that, it makes cravings worse, and you'll end up on a binge, which you don't want either.
You should start exercising. It doesn't have to be anything amazing, there are people who've lost plenty of weight just walking for at least 30 min. a day. Maybe some weight lifting on the side. Again, you don't need to lift like, 70 pounds, just whatever works for you.
I'd also recommend calorie counting. For losing weight, most people eat around 1500 calories a day, some more, some less. But you definitely don't want to starve yourself.
Weight loss isn't just losing weight, it's getting healthy too!