B String Buzz. Easy fix?
 

Hi. The b string buzzes from the 1 to 4th fret on a new D18. Would this be something easily fixed with a small truss rod adjustment? Or should I be taking it in to a tech?

Could be not enough relief. Check relief and if there's not enough, loosen the truss rod a quarter turn

Stupid question. How do I do that? :D

Martin truss rods are a little hard to get to & require a special Allen wrench, but if it is just one string, it is more likely that you have a nut slot cut a bit too deep. An easy fix, but based on your question about the truss rod, you should probably take it to a good tech ot luthier. Try to ask around & find a well qualified person. Don't just walk into a big box store & assume that they have someone who is competent. Tell them about your buzz issue, & ask them to check out & properly set up your new D 18.