Does the acceptance of my repentance depend on my confessing to people I have lied to, and what if I am unable to inform all of them; will I then face them on the Day of Resurrection?

If the lie does not cause harm or injury to anyone, then you are not obliged to confess to them what happened. It is sufficient for you to repent to Allah Almighty, for Allah accepts repentance from His servants and forgives sins.