Does an unsaved person need to worry that they can't be saved unless God elects them?
No. The unsaved person does not have to worry or fret over election or God's foreknowledge, as though they had no chance unless God elects them. The 'whosoever will' invitation is open, and the door is at ground level before every person.
Les explains that the whole concept of election and God's foreknowledge concerns who would become believers, but the unsaved person does not have to worry about it or fret over it. He illustrates from John 10's shepherd and sheepfold: no one comes into the sheepfold except by the door, and that door is at ground level. It is not on a high sheer cliff, across a raging river, or beyond an impossible mountain range. The door is in front of every human being, and all they have to do is choose to go through it. If they do not, it is not God's fault, and no one will stand before the great white throne claiming they never had a chance.