First Grow Ever

This is my very first grow, I have a tiny 60x60x120cm grow tent, so I refuse to be worrying about measuring CO2 or pH... or to be working out how much exactly nutrients I have per ml. I do measure temperature and humidity, but to record it? I beg, I am no professional. Technically one of Norther Lights is now 7 weeks old, but it had a very difficult start to its life as I had a very weak light AND my friend almost killed it by accident. As a result it is virtually the same size as its older sibling and when I repotted both plants to their adult pots, they had same size roots and the older one looked rather poorly, but it bounced back beautifully since. The light is on 21hrs a day and I set their night period for late evening so for the 3hrs of "night" I open the tent and the window in the room its in, so it's colder and to get more fresh air in. I don't currently have intake or exhaust fans, but I keep a net "window" at the bottom of the back of the tent open and there is an oscillating fan inside the tent so I don't stress over it. I can buy those later, for now my plants are fine. My plan is to keep the current light schedule and LST autos so they don't get too tall, while topping & shaping the other plant to ScrOG it after autos are harvested and then switch to 12-12. If needed I'll ScrOG Medical Mass earlier on some homemade net covering half the tent, cut it after I harvest my autos, move the pot the the middle and weave the branches through a store-bought ScrOG net covering the entire tent. I think this extra long veg for Medical Mass should result in lush ScrOG filling the entire tent.