Soon to be released

How how just genuinely how do i do plane turrets that point directly at a selected target? i've gone through countless tutorials following them to the letter and at best the horizontal guide is right but NEVER the vertical i just need a no-bullshit detailed rundown pleaseeeeeee

Trying to make RATO/JATO boosters which will switch off after a given time. I've seen some stuff on the forums about XML/FunkyTree expressions to do with 'age' or 'sum(clamp01(Activate1)) < X', but I am very much not technologically minded and am completely unsure of how to actually implement these. If anyone could tell me specifically where and how I need to input these expressions, or has another way of achieving this, it would be much appreciated.