Re: beginner got a good set up?
Fly casting is a little different from spinning and baitcasting, where the weight of the lure loads the rod and the lure sails out pulling the light mono line off the reel. In a fly fishing cast the rod is actually casting the weight of the fly line, the "lure" or fly just goes along for the ride. Since the fly is just some feathers or hair on a hook, it doesn't have any weight to load the rod for a cast.
When people talk about the "weight" of the fly rod, in most cases they're talking not about the actual weight of the rod itself, but the fly line weight it's designed to cast. It's pretty important to match up the weight of the rod with the weight of the fly line--- a 6 weight rod would generally cast best with a 6 weight fly line. (It'll still "work" with a four weight line but might be a bit more difficult to learn on.) That's why your post is a little confusing. Maybe you could answer a couple questions and we could help you out....
Is the Heddon rod fiberglass or bamboo?
Is it in good shape-- no missing or cracked guides? Ferrules seat together well? Is there a "set" or bend in the rod? Could you post some pics of the rod and Martin reel?
Depending on the condition you may have a decent rod from a collectors point of view--- in any case the Martin reel if it's in decent condition is probably worth the twenty by itself.
It sounds like you got a reel with four weight line on it when you bought the medalist, but did the Sports Authority fly guy load a 6 weight line on your new reel or the Martin? You have two fly lines now correct? What is the model number of the Pfleuger medalist reel you got at the reel repair place? (This will maybe give a clue as to what the fly line weight might be)
Did you take the rod along with you to Sports Authority? If you did, the fly guy probably matched it up with a 6 weight fly line properly. Did he try casting it? If you didn't take the rod along to the store the 6 weight fly line may have been a guess (a reasonable guess though). It sounds like he did a good job rigging up the Pfleuger reel with the backing, fly line and leader
Do you know what the name (or price) of the 6 weight fly line is by any chance?
If the rod is in decent shape, you may want to take it out on the lawn and have a go at casting. Maybe the fly guy could give you some lessons to get you started?
You might want to check out a couple youtube vids to get your head around the casting thing. Google "Tight lines fly casting part one" for the first of a 3 part series on fly casting. It's pretty good.
Todays graphite rods are pretty advanced, so you may want to get a new one at some point. A six weight rod would be a good match for your new 6 weight fly line and Pfleuger or Martin reel, and would be good for trout and small bass. A four weight rod and line would be more of a light trout and panfish and might be a tad more difficult to cast while you're learning. There are lots of good rods out there for around 100-150 so folks here can give a lot of recommendations for what to put in your letter to Santa.
If you want to take a crack at answering some of those questions, we can probably give you some more help on sorting out the stuff you have...