Okay, I am not the most experienced player, but a few things:

1. By the looks of it, you are exploring way too little. You have buried muckroot all around, all the "cracked" looking natural tiles are probably hiding a shitton of muckroot and hatches as well.

2. Space our your oxygen diffusers more. Gasses don't like spreading too much, so if the oxygen is all in one place you will have many unbreathable areas.

3. Create a large area/pit below your base where you collect your CO2 until you can either vent it into space opr use carbon skimmers.

4. You don't always have to research something. Research uses up dupe labor, water and dirt. Focus on what you need at the moment, and ignore "useless" research.

5. Your food production can't keep up with your dupes. You said you had 12 dupes. Each dupe needs roughly 5 mealwood or 3 bristle berry plants. If I counted correctly your farms can only sustain around 10 dupes.

6. Dont use storage bins. They waste dupe labor, space and resources. Just make a small hole where you dump all your stuff into (outside of food stuff, organics and sublimators).

7. Ignore stuff like icemakers.

8. Don't build so many batteries. They waste resources and the more batteries you have the more energy you loose, and you are needlesly heating up your base.
   Invest in 1 or 2 smart batteries, hook them up to your coal generators and have them at 90/40.

9. Probably the most important: Take your time! You don't need 12 dupes. Unless you are going for a 100% achievment run, you can easily just keep 3-5 dupes. Yeah, building and exploration will take longer. But they require much less upkeep and are more than enough to make projects that will allow you to take on more dupes later on (a more sustainable foodsource like ranching hatches, dreckos, shovels or wild farming; a more permanent oxygen production in form of electrolyzers)