What is the proper next move for white?
Q+A for beginners(and everyone else)

As Black which is easier to defend.
A. 1. e4 e5 2.Nf3 Nc6 3. Bc4 Bc5
B. 1. e4 e5 2.Nf3 Nc6 3. Bc4 Nf6

As Black which is easier to defend.
A. 1. e4 e5 2.Nf3 Nc6 3. Bc4 Bc5
B. 1. e4 e5 2.Nf3 Nc6 3. Bc4 Nf6
Both are easy to defend for those who have studied the defense and hard to defend for those who have not.

As Black which is easier to defend.
A. 1. e4 e5 2.Nf3 Nc6 3. Bc4 Bc5
B. 1. e4 e5 2.Nf3 Nc6 3. Bc4 Nf6
Both are easy to defend for those who have studied the defense and hard to defend for those who have not.
Which would you choose as White? As Black?

As Black I usually play Nf6. As White I don't mind seeing either defense, assuming I don't know whether my opponent is booked up on either one.

As Black which is easier to defend.
A. 1. e4 e5 2.Nf3 Nc6 3. Bc4 Bc5
B. 1. e4 e5 2.Nf3 Nc6 3. Bc4 Nf6
If you know what you're doing it doesn't matter.
If you don't know what you're doing? Black is better off playing 3...Bc5 since white cannot play 4.Ng5, and you avoid all that fried liver crap.
Just my .02

To avoid e4 e5 craps, I never played e5 except against players 200 below me.
I only play against players 200 below me. Despite being only 1400 there is nobody even near my rating

what is the f-file for? how can you use the space/squares? why is it valuable?
and how can you take/control it without appearing to weaken your king-side castle, as white?

We'll ever see a King's Gambit in a WC match again?
WHY HAS MY QUESTION NOT BEEN ANSWERED YET? Don't make the lion get ANGRY!

We'll ever see a King's Gambit in a WC match again?
WHY HAS MY QUESTION NOT BEEN ANSWERED YET? Don't make the lion get ANGRY!
No need to get angry. Here is a web site where you can find the answer to your question.
http://www.psychichotline.us.com/

We'll ever see a King's Gambit in a WC match again?
WHY HAS MY QUESTION NOT BEEN ANSWERED YET? Don't make the lion get ANGRY!
I don't think it will ever be the "main repertoire" for anyone in a WC match; it is simply not shown to "prove" enough compensation for the pawn gambited. However, I would like to think that computers haven't completely destroyed the romantic era attacking games - I wouldn't be too surprised if one or two King's Gambit games were thrown into a future WC match. Although it may not be the "best option" centipawn-wise, it does have a ton of theory and great psychology. If we ever see this opening in a WC match, just imagine the psychology the opponent must face: it is the same reason that Nakamura has dabbled into the Wayward Queen attack and why Carlsen has used 1.a4 at times.
The reason why we don't see the King's Gambit too often anymore is simply due to two big reasons in my opinion:
1) There are "stronger" openings White can go for an advantage (at least my computer thinks so anyway)
2) The King's Gambit has more-or-less been refuted by the line Bobby Fischer came up with and later refuted also by the Falkbeer Counter Gambit.

@KeSetoKaiba I would hardly call the Fischer defense to the kings knights gambit a refutation. It is still very hard to play and the positions that arise give practical chances for both sides. Theres also a few more moves that sidestep the Fischer defense completely. It is a good defense though.

@KeSetoKaiba I would hardly call the Fischer defense to the kings knights gambit a refutation. It is still very hard to play and the positions that arise give practical chances for both sides. Theres also a few more moves that sidestep the Fischer defense completely. It is a good defense though.
Perhaps "refutation" does sound a bit strong worded, but it certainly deters use of the opening. Additionally, against the King's Gambit I personally like the Falkbeer Countergambit; it has a good reputation and scores quite well against King's Gambit players. The point is that due to options like these that Black has, White doesn't appear to gain enough of an advantage or initiative out of this opening. When the smoke settles, if Black knows what they are doing, White is just left with a weakness from the f-pawn pushed so early.
I like the King's Gambit, but I don't think it will be in a WC match; if it is, then it will likely be a surprise weapon, but not the opening of choice.

[Event "TarunIyer vs. alejan0129"] [Site " Chess.com"] [Date "16 Mar 2019"] [White "TarunIyer"] [Black "alejan0129"] [Result "0-1"] [WhiteElo "941"] [BlackElo "946"] [TimeControl "1 in 0 day"] [SetUp "1"] [Termination "TarunIyer won by resignation"] 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Bxc6 dxc6 5. Nxe5 Qf6 6. Nf3 Bc5 7. d4 Bb4+ 8. c3 Ba5 9. Nbd2 Bg4 10. h3 Bd7 11. O-O O-O-O 12. b4 Bb6 13. Qc2 Ne7 14. e5 Qe6 15. Ne4 h6 16. Ba3 g5 17. Rab1 Ng8 18. Qb2 f6 19. Nc5 Bxc5 20. bxc5 b6 21. cxb6 Kb7 0-1 Sent from my Android how can white mate in 3?

[Event "TarunIyer vs. alejan0129"] [Site " Chess.com"] [Date "16 Mar 2019"] [White "TarunIyer"] [Black "alejan0129"] [Result "0-1"] [WhiteElo "941"] [BlackElo "946"] [TimeControl "1 in 0 day"] [SetUp "1"] [Termination "TarunIyer won by resignation"] 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Bxc6 dxc6 5. Nxe5 Qf6 6. Nf3 Bc5 7. d4 Bb4+ 8. c3 Ba5 9. Nbd2 Bg4 10. h3 Bd7 11. O-O O-O-O 12. b4 Bb6 13. Qc2 Ne7 14. e5 Qe6 15. Ne4 h6 16. Ba3 g5 17. Rab1 Ng8 18. Qb2 f6 19. Nc5 Bxc5 20. bxc5 b6 21. cxb6 Kb7 0-1 Sent from my Android how can white mate in 3?
Pasting into Stockfish answer to the rescue
We'll ever see a King's Gambit in a WC match again?