I have several friends that swear by geocaching as the best outdoor hobby ever. I think it sounds like fun, but they all use expensive, dedicated GPS units and pay/membership sites for cache listings.
I'd like to try caching for free/low cost to see if I like it before I invest in the more expensive goodies.
Any recommendations for free geocaching resources/apps I can play around with?
If you've got a smart phone, you've got a GPS. There are several apps for phones that work well (I'm told). Some are even free, albeit with some limitations. I haven't done it (yet), but it sounds like an inexpensive way to start out and see if you like it. Here's a link to an evaluation of the "top" four: https://hobbyhelp.com/geocaching/best-geocaching-apps/
I have done quite a bit of geocaching prior to 2011. I found somewhere around 1,000 caches and hid about a dozen caches. I found www.geocaching.com and the forums there to be a great source of information. I did pay for premium membership after my first hundred or so caches, but the free membership provided everything I needed to pursue the hobby.
I don't have any experience with the GPS apps for smart phones. I used a very basic GPS to get started and find my first several hundred caches. Later, a color mapping GPS made caching much easier.
Start with finding caches in an area that you know well. Look for caches that are not micro size and have easier difficulty ratings. Maybe start with caches that have been placed by very experienced geocachers. Use the GPS to get you within about 20 feet or so and then start using your eyes and intuition. Read cache descriptions carefully. Bring a pen and some trading swag.