This is my first experience ever with coding and overall, I find the course extremely insightful. However, starting with Project 2, it mostly feels like I'm just copying and pasting the given lines of code into Xcode and just reading the explanations of why something works in that way instead of being able to predict what should come next. By this point, should I already have memorized most of the commonly used lines of code and be able to fluently write certain functions? Should I go back to the beginning and re-do the activities to get a better grasp of things? What I'm afraid of is that I complete the entire 100 days but feel like I'm unable to create even a simple app without having to constantly go back to the lessons because I don't remember how to write certain things.

Welcome to HackingWithSwift!

What I'm afraid of is that I complete the entire 100 days
but feel like I'm unable to create even a simple app without
having to constantly go back to the lessons because I don't remember how to write certain things

Have you memorized every recipe in a cookbook?

Even experienced pilots use takeoff and landinging checklists before each takeoff and landing. It doesn't matter how many times they've flown!

If you need to refer to a recipe book to bake a carrot cake or refer to your notes to remember how to use an array, or how to setup a Slider or a Button, big deal. Use your checklists!