Photos and autos together (first time growing autoflower)

Two tents is the answer. One on 12/12 and the other 18/6 containing autos and vegging photos. In your situation and to give you an answer. Already said I think but get a good few clones of your photo and get them rooted and vegged some. Then when your autos are done you could have a tent full ready to go.

NEVER grow autos and photos in the same tent! Photos won't flower at 18/6 and autos won't perform properly at 12/12. It is one or the other and never both! Your best option is to start a second tent.

If you aim to cultivate photoperiods and autos simultaneously, I suggest beginning with the autoflowers. Once they enter the flowering stage, introduce the photoperiods to your tent. This allows you to switch to a 12/12 light cycle only during autos' harvest, ensuring optimal yields. It's an effective strategy for maximizing yields.

You can run your autos on 12/12...but they're gonna underperform. You could also just keep them in veg until your autos are done. Let them get bigger then take some cuttings to clone and propagate in another area, that way you can have a second batch of Critical to stick into the tent once the first finishes.

Autos still grow under 12/12 your criticals wont fliwer under 18/6 , think answer is obvious. I did start for few weeks autos under 12/12 , then letted them to 18/6 , saw no stress. Had your situation, conclusion was not to grow autos ;)))) they perform bad if not given best environment, but you kind of have no way ...