What should I use to fill in holes in my lawn?

I pulled out a lot of weeds as they were growing so tall and rapidly. Now I have a number of holes in my lawn. I called the company that is supposed to fertilize/weed my lawn for me. They said they aren't coming until May and in the meantime to just leave the weeds alone (lol too late I already pulled many). Would filling the holes with plain old top soil be ok? If grass doesn't grow back I can just plant some seeds there in the fall right? Ughhh lawns can be so stressful. I have no idea what I'm doing...any help/advice would be appreciated.

I have a section of the front lawn that needs to be filled in. I'm going to try Scott's Turf builder or something similar. The risk is that the re seeded section has a different colour and texture. But I am a newbie like you. I have put it off fearing frost but maybe this weekend.

Two weeks ago, I had some ample quantity of black soil left over from the flowerbed feeding so I pour some of it
into the holes left by the creatures that dug grubs out of the lawn. I don't have access to the grass seed at home but the lawn tends to manage to grow grass fairly readily as it's an older established lawn (with various dandelions, crabgrass, clover, etc).
You may wish to heed @avoncallingu 's mention of using a specific lawn product since you have the new lawn. Good point about different grasses but it's not something the average person knows the name of (except that it's not the lawn bowling or golf green grass that has to be kept super short).