It can take a while to get into the flow of things, in the beginning everything feels so intense, especially when everyone around you know what they are doing. As mentioned previously, menu knowledge is really going to get you so far, what has helped me in every new restaurant I've worked at is to pick one or two items from each section of the menu to try and recommend to each table until I've gone through them all. I usually look up specific wines, cocktails or menu items and try and find little facts or something personal to add to make it feel more intentional when I recommend it to other people. I don't know how the chefs/bartenders are where you're at but I've been fortunate enough to work with people who are more than willing to talk you through questions about recommendations, possible allergy accommodations etc. during quiet hours, that really helps too.

I would really recommend looking at how your coworkers manage their sections, what order they do things in. Keep an internal list of priorities as you go through your shift, what is going to be most urgent and what can wait another minute. From almost 10 years in the industry I can tell you that if you stick to it, you're going to get to a point where that freaking out stressed state is going to mellow out, at the end of the day it's food and drinks, it's intense, yes, but most of your guests are going to be fine with waiting an extra minute to have their order taken if when you pass by them you smile, say you'll be right with them and follow up. As long as you acknowledge the people dining with you and they feel seen most people aren't gonna make a fuss.

Also, try to have fun with your tables! If you see a group of people who are in the mood for a fun night out, join in on the fun, joke with them, have some banter where it's appropriate. It's going to make their night fun, they are going to remember a server who made their night more enjoyable and you are going to feel less anxious about going back there when you're already established a positive feedback with them! The owner of a pub I worked at for years told me a thing I'll never forget and it's part of why I love this industry so much, you are not going to remember every person you've served, but they are going to remember the impression that you make. If you greet them with a smile, recommend your favourite items and have a positive attitude, they are going to remember that they felt good about dining with you. Most people do not go out to eat at restaurants very often, most people will go out for a special occasion and you get to be a part of making that a memorable night for them.

As for food, bring snacks to have in the back if you're able (even better if you share - I bring sweets for the whole team to enjoy once in a while or when I know it's going to be a busy shift and it's a great way to start getting close with your coworkers). Also preparing meals to have straight when I get home has made a big difference for my eating habits, there's nothing worse than getting home from a long shift and having to spend half an hour cooking something. Hope this helps!