Decide how many meals you need to prep and for how many days. Beginners should prep a max of 2 meals per day so that they can build their confidence. Start small! ...
Build a food list! Decide which foods you want to eat. This is easier than building each meal individually.
Be cautious of making a diet plan, and dontevertrytostarveyourselfasitonlymakesyouevenmorehungrierandyou'llendupeatingafeast.