One beside the bed, one in the kitchen, and one near the front door.

For oven fires turn off the oven and shut the door. An oven is a fire box, it will contain the blaze. The oven probably isn't completely airtight but it should be close enough that the fire will use up the oxygen and extinguish itself quickly (the vent will pull hot air out but not let cooler air back in). Let it sit for a while and cool after you can't see flames anymore to make sure the fire doesn't reignite when you open the door and let fresh air in. Fire can damage the elements and seals so the oven needs serviced before being used again but so long as the fire was only inside the oven it should be repairable.

Make sure your fire extinguisher has the right rating for the place it is stored. For the oven grease fire, and most kitchen fires, a class K extinguisher would have been most appropriate because it is designed to put out cooking oil fires with minimal splashing.

https://www.nfpa.org/news-blogs-and-articles/blogs/2022/08/26/fire-extinguisher-ratings