A trellis is for support LST, a scrog is for training HST, to do a proper Scrog it requires more of a hard surface rather than a bendy net, and nets are more for support than anything else, Scrog is usually combined with HST, specifically topping to induce more branching. For beginners, LST can be a safer and more manageable option, as it offers good control without the risks associated with high-stress techniques. On the other hand, more experienced growers who are willing to invest time and care in the recovery of their plants can greatly benefit from implementing HST.
There is no right or wrong in learning so it depends on whether you have your heart set on a specific type of growing technique for future use. I would just put the net where you want it and keep bending branches across a square whenever one pops up past a point, try to use that as a guide for a week or two until you get a full canopy nice and thick, then slam her into flower hopefully everything will grow in unison.
Good luck.