Do a complete game in C++? +Resources

No, because transition rules in animation state machines use blueprints. That will correspond to incredibly small percentage of game content (0.1%?). Everything else can be done in C++.

Also, focusing on C++ will be very efficient if you know what you’re doing.

https://wiki.unrealengine.com/First_Person_Shooter_C%2B%2B_Tutorial
Also, this one was useful for me (you might not need it)
https://wiki.unrealengine.com/Animation_Blueprint,_Set_Custom_Variables_Via_C%2B%2B

You can learn by reading engine code. Books are very likely to be outdated the moment they’re released. Also you should tear apart project templats (ThirdPersonCPP, etc) and see how they work.

Hard to tell, but you may be fine. The team put some effort to make life easier for you (there’s garbage collector, for example), so you should be able to use C++ as if it were a scripting language.