Just a quick note on ornamentation in reference to an earlier point. Unlike the Highland pipes, the Uilleann pipes are able to play staccato, so in order to mimic many of the ornaments of the pipes on the whistle you’ll need to tongue, hold back breath and do other wacky things. One great local whistle player does a lot with his tongue when playing triplets - for example sounding out a “tach-a-tach” (like making a “tsk tsk” sound), so not just straight glottal stops and single tongue sounds. I know tonguing is frowned on for some reason, but when you do want to play staccato you’re going to need to cut that airflow off somehow.
As for fingering, a good start would be to learn some simple single-note cuts and rolls. Just play them slow and speed up when you’re able to play them rhythmically. Don’t work on airs, work on some simple jigs and polkas. As it’s been said, playing a proper air is one of the hardest types of tunes to play.