If you want to raise the action on the lower frets without disturbing the upper fret action, you may need to shim the nut. Hold down the 6th string at the 3rd fret and reach over with your right hand and tap the string above the 1st fret. You should hear a slight "click" as the string hits the fret. That will indicate proper nut height. If you are not getting that click, then yes, your lower fret action is probably to low and shimming the nut will help.
Be very careful with truss rod adjustments if you don't know what you are doing! No more than a quarter turn, then let the guitar sit for a day or two before adjusting again. Looking down the neck from the headstock: clockwise=tighten=will increase neck tension against the string tension, pulling the neck back to reduce forward bow. Counterclockwise=loosen=will allow the string to pull the neck causing bow (relief). Your guitar needs a slight bit of relief. A good way to check relief is to use a one of the strings as a straightedge by fretting the 6th string at the highest fret (probably 24th) with your left hand, reaching over and fretting the 6th string/1st fret with your right hand, and lightly tapping the 6th string/7th fret with your right thumb. You should see a slight space between the string and the fret.
Action is a by-product of bridge height, nut height, truss rod tension, bridge angle, and even the neck heel joint. All these things need to work together to get the action you are looking for. If you adjust one, sometimes you have to tweak the others too.
That is a nice guitar you have. You might want to save up $25 and take it to a pro.
.j.
Oh yeah, do these adjustments with a new set of strings. You'd be surprised at some of the weird things old strings can do to a guitar's playability.