You definitely succeeded in your goal: to use the skirt is a casual, but still polished way. The denim and brown leather gives just a bit of "flannel shirt" vibe to the plaid, and the fits are tailored and crisp, which retains the sense of polish.
Heartfelt congratulations on your new job! I'm sure it will take several weeks to hit your stride. If you take photos, you can always group your outfits into posts as Aida and Sveta do! Be gentle to yourself --- I think we wear out much faster in a new job or routine. Being in Learning Mode is like driving in overdrive -- it takes more gas!