When is it safe to bring out king and use it as a fighting piece ?

having how many pieces on chess board is safe to bring your king out of castling and make it a fighting and also is it safe bring the king out in queen's end game ?

you are funny just like chandler bing

Your king becomes a fighting piece in the endgame.

and when exactly to consider a it as an endgame ? i know its a stupid question to ask but i am just a beginner please help out . after losing how many pieces on board it is considered as endgame and is it safe to bring out king in queen's endgame ?

When most pieces are gone and the goal now is to defend pawns and attack others at the same time

so when queen's are off board and may there is combination pieces which cannot checkmate like rook and and knights or knights or may just maybe bishop and knight i know you can checkmate with those two pieces but its quite difficult .right ?

I think you're trying to figure things out that are beyond your abilities at the moment.  You're asking question on how to deal with pawn pushers, and when the king becomes a useful fighting piece?  

You need to srtick to the basics for now.  Ya gotta take things one step at a time.

Opening Principles:

1. Control the center squares – d4-e4-d5-e5

2. Develop your minor pieces toward the center – piece activity is the key

3. Castle

4. Connect your rooks

Tactics...tactics...tactics...

Pre Move Checklist:

1. Make sure all your pieces are safe. 

2. Look for forcing move: Checks, captures, threats. You want to look at ALL forcing moves (even the bad ones) this will force you look at, and see the entire board. 

3. If there are no forcing moves, you then want to remove any of your opponent’s pieces from your side of the board. 

4. If your opponent doesn’t have any of his pieces on your side of the board, then you want to improve the position of your least active piece. 

5. After each move by your opponent, ask yourself: "What is my opponent trying to do?"

When you're playing games like this, you shouldn't be trying to figure out when to use the king.

thanks for your advice sir and in that game i was trying new openings other than D4 was just trying to be creative i know i should work on my openings . There are also few good games i had like this one . but i get your point.Thank you so much 

hmm then what shall i do to improve ?

See Post #9

yes sir i get you point thank you so much

Hmm. You already got good advice, but let me try to come up with something.

Lets say knights and bishops are worth 1 each, rooks are 2 each, and the queen is 3.

Count your opponent's pieces this way and then:

5 or higher:  Probably not safe
4: Somewhat safe. Can come to center files, but maybe not center ranks.
3 or lower: Probably safe to go to the center and be a major fighting piece.

Just queen and pawns vs queen and pawns? Yes.

You might not be able to win, because of perpetual check, so when you have an advantage you often want to stay hidden behind your pawns, but when you're on defense, it's often necessary to bring your king out in the queen and pawn endgame. You might not win, but you're not going to get checkmated in the middle of the board. If you lose it's probably because they promote a pawn.

Capablanca had typical king play

https://thechessworld.com/articles/middle-game/5-capablanca-positions-that-you-must-know/

I asked this question because this catastrophe happened how do i avoid such mistakes in the future 

31.Qxa4 was bad because counting... that has nothing to do with chess, just count.

yeah i know man i really screwed up there anyway thanks

23. Qxd5+