I understand your confusion, since there are two verbs "to lie." First of all, it's "lie" as in to lie down (lie / lay / lain), and is not the "lie" that means to speak falsely. "Ahead" just means in the future.

Lie(s) ahead means: going to happen. Example: I'm excited by what lies ahead - I'm excited by what's "going to happen" Are you worried about the things that lie ahead? - Are you worried about the things that are "going to happen?"

Can be used like 'what lies ahead' - it means 'what will we find out/discover/come across/uncover/what will happen' etc.