You have to start some where, asking for critique is a way to get input from others. You like most of us have trouble mastering light in different places. I have the same problem, but with experience you will recognize and learn to handle each situation. One of the hardest things to learn is exposure compensation. You maybe should bracket your exposure and go to the aperture priority mode. I started my granddaughter into photography just a few months ago and stressed to her the importance of it. With light changing in scenes that you were shooting, the lighting is not constant and changing by the minute or even seconds. Shooting with continuous shooting can also work at times. Over all not a bad job, most were over exposed but that can be handled by experience.

I would be interested to hear what your instructor says about these. Personally, I use the word "portrait" in a traditional sense and style, so much of what professionals do would not be my idea of a portrait--even when they are good pictures of people. The one sitting on the window sill looking out is the closest to what I consider a portrait. The one in the overcoat is close to what I consider fashion photography. Your textbook ought to have a chapter (or more) about lighting portraits--the different types and the appropriate balances between lighter and darker sides, etc.