The strongest designers are in the habit of always learning from mistakes. They learn from their own mistakes and from the observed mistakes of others. Even if we see something we think is good or we think is okay, if we push the creative side of our personality, we will think of other ways it could be done. Imitation is natural and easy. Innovation requires hard work and imagination, but can truly make the world a better place.
Some students find it very helpful to discuss the field trip with another student in the class.
You may find that you agree on some things. If you can discuss your disagreements, you will probably get ideas for your journal. Sketches are very appropriate to help illustrate your recollections and your ideas for changes. Any two houses seen are going to have similarities and differences. Try making some comparisons.