I'll toss in my 2 cents regarding line weight. The only thing that a 4 will do better than a 5 (In terms of fishing), is present a fly more delicately. That does NOT mean that a 5 isn't a delicate rod. A 4wt might also be less work in terms of casting after a long day, but some 5's can be as easy to cast as some 4wt's: it depends on whether it's a stiff 4wt compared with a moderate 5wt. That's all junk you can worry about down the road, however. Even though it's cold right now, you can take your 5wt into the backyard and practice casting. Practice for accuracy, then into the wind, with the wind, and distance. When the temperature goes high enough for fishing, you'll be set in terms of getting the fly on target.
You can buy a cheap line to practice with. If there's snow on the ground, it won't bother your good line. Grab one of the Allen lines in the forums Classifieds for $12. Posters report that they like them, and that's about as affordable as it gets.