You can do it, Jokaman. The most important skill I've learned for outdoor exercise is to stop caring what other people think. 99% of the time, they're way too wrapped up in their own affairs to care about yours. And the other 1% you'll either inspire, or they're not worth worrying about.
Enjoy the fresh air and sunlight, they make working out much more fun. Just enjoy the day and creating your own space; no need to kill yourself on the first day. If all you do is lug your stuff back and forth from the car, that's a good workout in itself.
Have fun, but don't wait too long, the sun is setting!