I've just had a quick poke around, and you can load up other people's work - there's a massive variety which shows just how much is in this simulation program.

You can load up simulations with the bottom-left icon, then hit the pause button that's bottom right to start them off. If any talk about "sparking" they mean use the SPRK tool to put electricity in the thing they're talking about - you can search for SPRK using the search tool above the pause button, or find it under the Electronics menu (second one in that right-hand side with the plug icon).