Get schooled in playing melodic in D! I've included many of the things that I've practiced to up my chops when playing fiddle tune melodies and improvising. The best thing for you to do is watch and listen to this video a ton, then check out the tab.
Learn the scales using a combination of tablature and video, and then attempt to figure out the fiddle tunes using just the video and your ears. Using tab for the songs defeats the entire purpose of this method!
Have fun and if you have questions, type them in the comment section below!