If you are just learning to cast then go with the WF line. With a 5/6 weight then you will probably find it easier to learn with a 6 weight line as you will be able to feel the rod load more easily. For leaders you can buy tapered leaders, or buy a few spools of mono and make your own. A pretty basic starting point would be a 9' leader as 60-20-20, 60% of the leader will be the butt section, 20% the middle and 20% the tippet, the line gradually decreasing in diameter as you reach the tippet so that the fly turns over nicely. A basic selection of flies would include woolly buggers, some leech patterns, hare's ear nymphs, prince nymphs, zug bugs, zonkers or some other sort of minnow pattern, and the adams is the universal dry fly.