If you need more help in Finale, their website has tons of information.
Make sure to check for a related Quick Start video - they are full of helpful information about the software, and if you run into trouble you might look there for some quick answers:
You may also want to check out the Finale User Manual website - it may be a bit overwhelming, but everything you could need to know is on there. If you are looking for a more extensive list of keyboard shortcuts, go to the "How do I" menu on this website.
There is also a very interesting Visual Index that allows you to hover over a musical concept shown in the context of an example score: