I popped my seed into a pot and then 4 days later ...

Seedlings and young plant like warm media to grow in. They like 22c+ . I've found 28c to be a happy place for them. Lower than 20c and you'll notice growth slow. <18c and it will crawl along. So 22-28c is best. Also, make sure your water is 22c-24c or you'll be cooling the roots and slowing growth when you water them. I got a heat mat recently for my Space Cookies (grow log on here) and it made such a difference I'm completely convinced they're necessary.

If they're buy an open window, perhaps put a dome over them to keep them ~28c with humidity ~60%.

But root temperature should not be overlooked.

Through the window little light gets. and the 12-12 mode will be slower than growth

Hi there! They’re asking for light! Growing nearby the window always result in slow growing twisted plants and poor yield. I’d recommend to buy a light or find them some great outdoor spots. I’ll be around, good luck with these babies!

Most of the pictures you are seeing are from indoor plants.
The rate at which your plants grow depends on environmental conditions like: light hours and intensity (outdoors you don't get 18 hours of direct exposure), temperature (in the correct range 23°C to 28°C (73°F to 82°F) the growth is explosive, below that it slows down a lot).
See how your seedling is stretching? That means it's not getting enough light.
The one thing you can do is take care not to over water