Growers generally report that autos require less nutes and slightly less light. 20/4 seems to be the best.
If growing in soil or soiless with added nutrients I say start seed directly in 3 gallon pot. I've used Ocean Forest and Roots organic. I preferred the Roots, but that's just me. It will seem like the plant isn't vegging that well at first because it is growing rotts in that big container. It will catch up though in the days to come.
Week 1 no nutes, but use root stim and ph'd water.
Week 2 ,3 1/2 strength veg and root stim
Weeks 4,5 Veg 1/2 strength, and bloom 1/2 strength.
Weeks 6, 7,8 Bloom full strength, or whatever you think your plant can handle.
weeks 9,10 No nutes, just ph'd water.
Most autos will likely be finished in week 9 or 10. Just keep an eye on the trichomes and watch for most of the pistils to brown. Some seed producers state the number of days from germination and some state the time in flower. 70 days from germination seems to be the magic number. Not all autos will get ambers from what I have read so you can't rely on this solely.
Overall they are very easy to grow. TBH you could just toss them in Fox Farms, skip the veg nutes and give them some bloom in 5.6.7.8 and they'd do just fine.