>>3341765Stabilizing footage in post isn't really "getting serious", it's pretty easy in Premiere at least.
I'd personally recommend the Sigma 30mm f1.4 and Sigma 60mm f2.8 as a starting lens kit, the 30mm f1.4 for walkaround shooting & low light and the 60mm f2.8 for portraits and a more zoomed in perspective.
For the portrait use, see pic related. Focal length changes how the face looks considerably, 85mm to 135mm lenses are typically the sweet spot to make a person look good. The Sigma 60mm f2.8 crops to a roughly 85mm lens so it's ideal for shooting people. The 30mm f1.4 not so much, it squashes them in a bit.