You can do well in COMP1917 with no previous programming experience.
If you do Electrical, then I really recommend you do 1917. If you do Civil, go with ENGG1811.
Consider the massive difference between Civil and Electrical and think about why you want to do either of them. Then try to make a decision early on because Civil and Electrical are vastly different and makes it harder to transfer between the two being so different.
I recommend for this semester, do MATH11X1, PHYS1131, ENGG1000, COMP191X if you are doing flexible first year. That way you can transfer into either for second semester.
Once you get to second semester, you'll be doing quite a few different courses altogether for each so I really recommend you make your decision before semester two commences.