definitely work on the roll cast, its easy, form a D shape draw a straight line from your rod tip to the water, and you line should form the curve of the D, and then just fire your rod forward, stopping with the tip at about a 25degree angle to surface of the water
stop your rod sooner on the back cast, you're stopping at 3 oclock, 10 and 2 10 and 2, another tip, start with more line out of the rod, if you have don't have enough line out, the taper will cause it to want to back track down the rod, instead of feeding itself out of the rod, so say 15 to 20ft of line out, or so that you can feel the taper thinning down in your free hand, that will generate more line speed faster and get that line firing out.
one thing that I did that helped me learn, was go a line size heavier than my rod, it helped me feel the rod load up a lot better and was able to time my casts easier, so now using the recommended line size, i know what to feel for