As mentioned, your first step is to get a leader. They make them in lots of diameters/weights, but mostly pick between "bass" or "trout" to get yourself started. So you'll want backing (optional, a braided line that gives you more length for big fights and bigger spool diameter for your line to wrap on) on your reel, tied to your fly line, tied to your leader, tied to your fly. I like the leader loops...slide it over the fly line and a shrink fit cover over it...very easy. I'm only guessing, but in my experience, a dark green fly line is often a sinking line, which might be best for a lot of lake applications where you want a streamer or bugger to go deep, but I find it much harder to cast vs. floating line as it's hanging downward in the water and more resistance under the water than on it. So if it's sinking, you may want to get some floating line while you get a hang of it. I fly fish from my kayak on lakes and rivers and it's a blast, but it'll take some getting used to vs. spinner fishing. If you stick with it and learn the ropes, you'll be grateful. Another great way to start off lake fly fishing is just with small poppers around structure and cover, you'll have more sunny and small mouth action than you know what to do with and since it's surface fishing, it is easier to see what's happening.

LMAO! I have seen this too many times to count. Newbie mistake #1, here bro, try this article

http://flyanglersonline.com/begin/101/
It will help, and look in this specificly, your doing it wrong.

http://flyanglersonline.com/begin/101/part6.php

Good luck, and if worst be, call a guide, they know how to help.

And worst of all, try Golf, its easier. lol

I would get a line that sinks to the middle, not too light, not too heavy.