The distance=..5 makes the command only target villagers less than 5 blocks away, meaning you can build a villager breeding room and place the command block in the middle of that. You can change the distance, of course, or remove it altogether to make every loaded villager ready to breed.
This may mean that the particles are a generic "error" notification when villagers are unable to breed, which is caused by a variety of reasons. Nonetheless, the solutions to these Reddit posts were to add 3 times as many beds as there are villagers, and to make sure the villagers have at least one full block of space above their heads.
Having just set up and used 2 infinite villager breeders I suggest keeping a large wheat farm near/in the village as the number of bread (made from wheat) needed to make villagers reproduce is significantly less than other options. Additionally once you have a farmer villager, the farmer will harvest/replant the crops and make/distribute bread for you. Note that all villagers with the farmer ...
So I got my villagers to make about 10 babies. However, my younger sister killed all the babies, and they won’t breed again. Do I need to give the villagers more bread? Break and replace the beds? ...
Business Insider: How to breed villagers in Minecraft and make your own town
I have always wanted to know how to breed villagers in Minecraft, i have tried looking it up, but it came up with loads of useless, out-of-the-topic things.
minecraft java edition - Why are my villagers attempting to breed (they ...