Yup, it is easier if some one else does the donkey work as DM and you get to see the other as a player initially.For my part, I have heard from enough people I trust to know that at least for certain games, Foundry is a better choice than Fantasy Grounds Unity (which is what I use). But I have realized that I just don't have the bandwidth to learn Foundry at this point. So yes, daunting.
If you bought your license directly from fantasygrounds.com, you would have had to register with them and there'd be a way to prove ownership - provided you still have access to the email account you used. If it was the older Fantasy Grounds Classic you bought, there's a discount if you upgrade to the newer Fantasy Grounds Unity. Even if you bought it via the Steam store, as long as you linked your Steam account with a Smitheworks/fantasygrounds.com account, there'd be a way to prove ownership. FGC was once upon a time also offered in CD-ROM format, but I wouldn't know if those are still honored....I even picked up Fantasy Grounds once, though installed on an older PC, I don't have anymore - maybe I can prove ownership and get a new download...

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.