Holding the guitar by the body with the neck pointed away from you, sight along the top of the neck with the fattest string (Low E) at the top. Most if not all guitars should have a small amount of what is known as "relief". This is a very slight curve in the neck of approx 2-3 mm. The direction of the curve is critical. The curve should be (I'm assuming that the Low E string is on top while sighting the neck and that this is a right handed guitar) in the same direction as if you took your left hand and naturally curved your fingers. Of course the curve will be very very subtle.
If the neck curve looks ok ( you can measure from the fret board to the lowest part of the string where you see the base of the curve in the neck) then some other problems could be low or high frets, action TOO LOW
If you dont have some relief, then LOOSING the truss rod will give you some. We are only talking about 1/8 to 1/4 of a turn at a time. It can also take several weeks for an adjustment you make today to fully be complete. This is wood and it takes tome to respond. Again 2-3 mm maximum when measured at the lowest point of the curve.
Again without seeing the guitar, its very hard to tell. My advice is if you don't know what you are doing, don't do it. Unless you don't like the guitar.
Sight the neck and describe what you are seeing.
One step at a time
