The best way to improve your CW is to get on the air! There's a lot of QRP activity around 7040, and most ops there are very tolerant of newcomers. If you hear a CQ, don't be afraid to answer, at a speed that's comfortable for you. Whenever I call CQ, I always try to respond at the same speed the station answering my CQ is using. I might call CQ at 17wpm, but if a station answers me at 10wpm, that's what I'll reply at.
Welcome to QRP. I hope you'll find it as addicting as I have.