Ah thats probly one of problems if getting stretching. Get a cheap grow light screw in bulb socket kind if doing 1. And keep it close to not burn them. Autos grow fast. From seedling to 1 week is huge. As can see in pics.
Germinate in the pot your growing. Autos dont like transplants. 3 gallon pot minimum. I use a 5 gallon fabric pots and fill about 4 gallons. Max 5 gallon. Autos grow so fast that they wont utilize all the soil if using huge pots. Autos usually done from seed to harvest in 8 to 10 weeks some strains maybe a week longer..
Autos are not photo sensitive. Dont require a light cycle like photos. If you only get 10 to 12 of sunlight your yields will be small. If plants stretch its because they want more light. There hungry and will stretch themselves until they fall over if light not adequate.
Also use a good soil to start and thats all the auto will need until flowering no veg nuts. After about 3 weeks when plants the start to flower start adding bloom nuts 3/4 less than what bottle says. Every other watering. Water only in between. After a week or 2 go half strength on bloom nuts and see plants reaction. Auto are not as nutrient hungry as photos. Always water only in between your nut watering. Some auto strains like some nuts but some hate it.. less is more on nutrients with autos.
My 3 plants now. Jack herer auto. Bubblegum auto and White Widow auto. The jack herer is a sensitive little shit to where the other 2 i could pee in the pots and they wouldn't care. Lol I don't pee in the pots by the way lol