How to spawn villagers in an nearly empty village?

If you have two villagers, trap them somewhere in a building that they cannot get out of and place doors everywhere inside the building. Also, place down beds inside the building and if there's two villagers, they will breed. But idk if you're gonna be able to do it without two villagers, try placing down several beds first to spawn a second villager. If you're in creative mode,(which you're probably not) use a villager spawn egg, found in the miscellaneous section. That's all I have.

Edit: you could place beds inside the villager homes.

You could try to find zombie villagers and cure them.

Zombie villagers are curable by throwing a splash potion of weakness at them, then giving them a golden apple (by using similar button controls that feeding animals uses).

If you've done this successfully, a loud crackling sound effect would play and the curing process starts; the zombie villager will have red potion particles, they'll begin to start shaking violently, and they'll have stronger attack damage so make sure that they're confined to a space.

It will take a couple minutes for the curing process to complete (though confining curing zombie villagers around iron bars slightly decreases the time wait), and when it's finished the zombie villager will have turned into a regular villager.

Once you have two villagers in your village population then you could choose to start doing traditional villager breeders, and you choose to continue curing other zombie villagers if you have the resources for it.