Am I obligated to do anything or offer expiation if I am unable to fulfill my vow to make and distribute bread and sweets to neighbors on Friday due to the unavailability of oil and the inability to purchase it?

Undertaking a vow is disliked. However, if one vows an act of obedience to Allah, they are obligated to fulfill it.

What you undertook falls under the category of a conditional vow, which must be fulfilled if the condition upon which it is suspended occurs.

If the non-fulfillment of the vow on the mentioned day was due to an overwhelming reason, there is no sin. However, the obligatory feeding must be made up on another day, not on a Friday, and according to some scholars, no expiation is required of you.