First grow with Training wheels

Greetings, all. I'll start by saying I've worked around these plants plenty after being contracted by several local LPs but never in my wildest dreams, say, 5 years ago, did I believe I'd be growing plants in my own home. This is absolutely a first for me - but I'm usually really good at growing tomatoes and zucchini.. so this can't be THAT hard - it's a weed! Started off by following instructions verbatim from Grower's Choice seeds. (I could go on and on about how poor of an experience I had dealing with this company but for now I'll keep it about my grow). I'm starting with 2 indoor and 2 outdoor (ie. 1 Tangerine Dream and 1 Critical Purple inside and 1 of each outside). Both strains are autoflower feminized. Inside/Outside because I'm curious about controlled vs uncontrolled. The seeds sprouted fast using the suppliers suggested germination method and within 3 days I had my indoors planted with my outdoors close behind (I'll plant them outside tomorrow). Grown in recommended herb/veg soil provided by a local greenhouse supplier in 20L pots. Tested ph/moisture using an Amazon purchased meter. Ph showing just a tad under 7 with moisture right in the green. The 'grow tent' is a mish-mash of items I had around the house - some foam board basement insulation (with the shiny reflective side on the inside) constructed into a box structure secured by a steel shelving unit. Dimensions are 4' wide, 5' high, 2' deep. I've sealed it using aluminum reflective tape and have an inline duct fan releasing the air outside. Phlizon 900W LED Grow Light purchased from Amazon. It came highly rated so I figured it can't be terrible. From everything I've read, an 18/6 schedule should be good. But I'm open to change if someone explains a good reason why. I'll do my best to provide updates as frequently as I can - more so to help me review my progress of this new hobby but hopefully helping some of you too (as you have helped me during my 'lurking' period). If anyone has any questions/comments for a n00b, I'm all ears. Fingers crossed for a Bountiful harvest.