Haven’t had oil in a while, but there should be a bleed valve at the furnace on the oil line. You may want to open it and let the oil fill a small cup. If oil is flowing then it isn’t your problem. It could be the igniter.

When we were buying oil, I used to use Standard Oil although there were many other quality oil companies. We also used to lock in prices which could help or hurt you. Standard would estimate when I need another delivery and just show up and fill it up.

Once, I ran dry. Guy showed up at like 11pm on a weekend. Poured in some oil to get me running for a day or two and made sure everything started up. Since we were a customer, the service was free and we paid standard rate for the oil and then the next fill up. He said that there is an on call technician with the truck at their house 24 hours a day.

Another time, my burner went and they came, replaced it and the fee was very reasonable.

You pay a little more but you get a lot if you can swing it imho.