SICP (Scheme) – Which parts to skip if only interested in Chap 4 and 5

Hi experts,

Background:

- Some non-professional experience with Python and C++;

- Completed all projects of the Python version MIT SICP course, EXCEPT for the last one (Interpreter) because I don't fully understand the implementation

For the Scheme version, I'm only interested in Chapter 4 and 5 (Interpreter and Compiler part).

My question are:

1. Which parts of Chapter 2-3 I can safely skip? I won't skip Chapter 1 because I need to get familiar with Scheme itself. I find its syntax awkward, comparing to the languages that I know. I heard there is some EE stuff so I'll definitely skip those.

2. I understand that all exercises are important, but what's your strategy if you are really stuck in some exercises? As self-taught, I'm very keen on a project-oriented path (really enjoyed the Python version course), but I don't want to skip all exercises.

Thank you!