The phrase "lay in store" refers to anticipation for future events and the preparation that comes along with it. It can be replaced by similar expressions, such as "be prepared," "await," "stockpile," "accumulate," "store up," "hoard," and "gather." All of these words convey the idea of having something ready for the future. Depending on the context, some of these words might work better than others. For example, "stockpile" and "hoard" could be used when referring to storing up supplies for a potential disaster, whereas "anticipate" and "await" are more fitting when talking about looking forward to an upcoming event.