You've been out of college for 6 months and you don't have a job - now is not the time to be picky. If someone hires you, you're taking the job. Period. The only way you're going to get into the exact line of work you want is either by a freaking miracle, or by getting a PhD in it. BSMEs straight out of college are pretty much scum (you're welcome). The fact that they want to pay you $60k+ a year is amazing. R&D, at least where I am (automotive) is reserved for advanced degrees. You can try, I would love to do that too, but don't hold your breath.

Side projects - it doesn't really matter, just make sure you have something to show for the last 6 months - either your life-guard/manager job, photography, programming, hobbies, etc. You can take free classes if you want, but I doubt they'll make much of an impression on employers, especially without that important piece of paper saying you've actually completed the course. Do it if you think you'll get something out of it.

I know I sound like some old, bitter person, but I'm <30 in my first engineering job. I've spent a few years wondering what I want to do, and wasting my time debating which specific area I want to get into. Don't waste your time. All you can do is develop a plan to get you to the doorstep. Once you're there, you don't have much of a choice who answers the door. But that first experience will help you out later, so even if you start out editing manuals (like I did), you'll see different jobs you might want to pursue. And when there's an opening, you'll be the first one at that door.

Anyway, priority #1 is networking. Ask family, friends, professors, neighbors if they know any working engineers. Hand or email that person a resume. Your school should have a career placement center, and you should still be able to use if even after you graduate, so put your resume out there, too. That's the second place companies go to find people; the first being those referred by current employees.

Good luck.