Just about any nutes will do the trick. Once you’re comfortable with growing you can try different nute combinations and manufacturers etc but for now just some basic nutes is fine. Don’t over water them. You can follow
@Emilya Green for how to water
The Proper Way To Water A Seedling In A Large Final Container
Did I mention don’t over water! Lol
Your plants will most likely find the optimum benefits from a 18/6 schedule for lighting. 20/4 is harder on them but not crazy. I’ve found personally there’s no need to ever deviate from 18/6 for the entire grow with autos. Just adjust intensity as you go if this is a possibility. If not, adjust the light distance to the top of the plants instead.
Can you try and get us some pics without the lights on? Very difficult to see any plant color with the light you’re using so it will make it very hard for us to look for deficiencies etc.
Keep your nutes % very low until you have 2-3 or more sets of leaves. That’s what works for me.
The key to growing: Patience! : )
Hope this helps. This is definitely the place to ask questions. I’ve learned soooo much from this forum. This place is amazing! Enjoy the ride. If you crash and burn on your first run chalk it up to experience and learn from it