Confused about functionality ...

[HasNoStyle]

I've messed around a bit with FG and I'm a little confused.
I cannot edit creatues too much just make new ones.. but I have to manually enter attacks, abilities, spells, equipment? There is no way to drag and drop?
Do I get drag and drop or more functions if I buy books?

[celestian]

Just grab the creature and drop it in the NPC window and it'll make a copy. You can then manipulate the npc as you desire.

[LordEntrails]

Do note, that there is no drag and drop onto NPC's, only PC's. Create a copy of what you want to modify like Celestian says, then just modify it to what you want.

[Trenloe]

Yep, create copies to edit NPCs.

Here's a video showing how to enter a NPC for 5E: https://www.youtube.com/watch?v=f-POluSDHAc