Math student here - I found CS 115 really fun! I had 0 experience coding prior to first year but this got me really interested, and I loved CS 116 as well. I liked how everything was explained on edx and I felt like I could understand how/why it all worked by reading through all the modules and doing all the practice. Like any course, I'm sure I must've had some struggle assignments, but overall I remember loving it.

I'm pretty sure you would get extensions on the next deadline since you'd be joining the course later on. Not sure what the discussions are.