You can have a low carb meal, do you know where you're going, if you do then see if they have a menu online you can check out? Salads aren't always the best option because they sometimes add in all kinds of extras that add up the calories and the fat content. If you can maybe have some plain chicken, a small steak, a piece of fish, just stay away from rice/pasta/potatoes and no sauces, and please dont drink alcohol, it can be dangerous to drink while you're in ketosis.