u/Accomplished_Elk9539

Mayday!! I need help is it savable? I have two plants one I think is infested with spider mites I've quarantined the other plant by taking it out of the tent but I have no clue what to do but I know little bugs on the leaf are BAD (3rd and 4th are the quarantined plant let me know if it's safe and what to do with it please)

I'm new to growing and I don't know how to really top my plant or when too, I know that it makes the plant wider and I know what it does I just don't know when to do it or how to do it, do you guys think now is good?

I just recently started and I'm seeing these little marks on my leaves along with a spider in the tent and am paranoid I don't have much knowledge and am trying to learn does anyone have advice for a new grower?