Just use the internet and browse around. Free online videos too.
As for GPS/NAV/COMS, you have Avidyne and Garmin. You can download their demos for free (I downloaded Avidyne simulator to my iPad).
There are aps to look for air traffic stuff on your couch, like FlightAware. And LiveATC to listen to current or past radio ATC transmissions.
There is ADSB that you can learn about. Shows you traffic and weather on a mobile device or tablet (or panel mounted GPS).
There are free and paid EFB aps that allow you to flight plan, check WX, airports, etc. Flight Plan Go and Avare are a couple. I pay for ForeFlight.
And there is actually a lot of ongoing development. Go to Garmin’s, Dynon’s, and other websites to be really enthused or confused.
And lastly, if you’ve never been to Oshkosh EAA Airventure, go and dive in head first.
Welcome to POA and back to aviation!