A basic rule as a waiter is to make sure that guests have their drink before their food is served. When guests arrive and are seated, at a fine dining á la carte restaurant, offer water immediately when they are seated at the table. This is so that guests never sit empty-handed, as the water is served, other drink orders are taken up. Here, as a waiter, you can make it easier for yourself and plan. Either you take their food order immediately after you serve their drink.
If you take both orders at the same time, it is of the utmost importance that their drink arrives before the food.