Great progress in here already!
As for finishing vs starting something new, I would it's case by case. Being able to finish works is a skill that takes practice to learn, and it comes with it's own challenges. So it is important to finish thing, but that doesn't mean you need to finish everything.
The best way to judge is to decide what/why you're painting that piece. Was it just to mess with brushes? Was it just a study? Were you just messing around? It can be hard to feel the drive to finish something that was never really meant to be a finished "piece".
So I would say try and come up with ideas for a finished thing, and then try to finish them. If that makes any sense haha!
Keep up the solid work, man!
