Resume Building Under Quarantine?

Hey guys, freshly accepted CE student here. Today I heard that the summer job that I had lined up at a summer camp has probably been axed by COVID-19. Although I'm a little annoyed because I'd have loved the job, it would admittedly have added nothing new to my resume. I'm hoping to try and take it as a sign and move towards doing something that will actually strengthen my co-op opportunities in the coming year. My question is though: what's the best way to go about doing this? A couple of my notable points:

- Decently advanced C++ experience - Passable Python knowledge - Summer volunteering over the past two years - Slight leadership experience

My weakest area is that I have not held a job in the traditional sense. If I were trying to work my butt off to make sure I land a co-op position, what kind of job should I be looking for? I could get work at a grocery store pretty easily. I know they say that some work experience is better then none, but is that "good enough"? Should I try and find a more targeted job or a more formal summer student internship?

People talk a lot about side projects as well. What kinds of things are you guys doing? Open source contributions? Are you leading your own projects? Is it worth my time looking into for a first term coop placement?

C++ is certainly my language of choice since that's what I've been taking classes in at school. Should I be trying to brush up on Python? I've heard finding C++ positions can be challenging. Are there any certifications I can chase?

If any of these questions are redundant or there's somewhere else you can point me to, that I haven't seen then please let me know. Thanks!