Does taking AP Computer science Principles and taking a coding class offered by external school look good for CS MAJOR

Of course. Both activities relate to CS majors but I want to point out to you that AP Computer Science Principles is incredibly easy like a middle schooler can do it and that is why many colleges, at least the ones I applied to, don't accept the AP test score for credit. I recommend taking AP Computer Science A instead or something more challenging and valuable. I recommend to also start developing a portfolio to show off during college applications like make websites for school clubs or whatever. I know people at my school who even designed websites for companies like law firms (which is insane).

Hey!

It sure does! It shows that you have been tracing the path for your professional career since your trajectory in high school. However, it would look even better if you took those classes and combined them with a closely related EC. That way, you show a more established profile for the university to see and truly show you interest in the CS major and everything that comes along. Also, I would recommend you look for activities and events such as MIT's or Harvard's hackathon which will look really good on your resume with the side benefit of being a great deal of fun. I wish you all the best and I hope you find the way to create that profile you're looking for!

Best.