No. It's a lot of unnecessary work. Study for them, sure; do the Skillport modules , even though they aren't super helpful. If anything it'll knock out some busy work for you during the course. I'd recommend buying Passport books for both Net+ and Sec+ (Net+ passport book) and using those as your main study material. If you hit that hard before you go and for the month that you're here before you take the certs I'm 90% sure you'll pass.
If we are talking about which class to take, I would say take the programming class.
I say this not because its more valuable, but because programming can be harder to properly learn on your own. If you have a good instructor he will stress things such as the importance of commenting your code and writing it so that its modular and therefore easier to reuse in other applications you may write later. These are concepts that many people who are self taught struggle with in the beginning.
For the networking part, I would simply pick up book such as the Mikey Meyers Network+ study guide and read it in your spare time. It shouldn't take you more than a month or so of studying to get to the point you will be able to pass that exam.
I took the Net+ in November before I enrolled at WGU. I read through the Mike Myers Network+ Passport book and passed the exam no problem YMMV
https://www.amazon.com/CompTIA-Network-Certification-Passport-Authorized/dp/0071789057