what is the best opening?

try scotch gambit

try Halloween gambit,cuz November is coming, nah jk, because it's easier to learn and not boring for me

I’ve tried a lot of different openings, and after trying them out I play trompowsky and Kings Indian, I’ve also posted about these openings with my previous account.and you should choose the one that suits you the most. I really like milking with the Kings Indian, it used to wind everyone up, and milk come. Thanks

The Czech Defense. Because White usually has no clue.

Bongcloud and Janko gajdosko haymaker system

This is COMPLETELY the wrong approach and VERY BAD ADVICE.

You DO NOT EVER base choice of opening on any assumption that your opponent will not know it. Always assume they know it!

You need to UNDERSTAND, NOT MEMORIZE the openings you play. I will play 1.b4, 1.c4, 1.d4, or 1.Nf3 with White. I no longer play 1.e4 because of certain openings that I have issues with understanding. I do not play 1.d4 Nf6 2.c4 (always 2.Nf3 if 1...Nf6) because of my issues with the Grunfeld. I avoid the Grunfeld and the Alekhine like the plague because I have trouble with what is known as the "Mobile Center", whether having it or facing it.

You need to think about openings based on the central pawn formation. Openings should not be compartmentalized like one has nothing to do with another.

Take the Sokolsky. The vast majority of lines overlap with other openings.

The Exchange Variation is its own ball of wax. You would need to study 1.b4 e5 2.Bb2 Bxb4 3.Bxe5.

The rest are just like other openings:

1.b4 e5 2.Bb2 d6 3.c4 and now 3...f5, 4...Nf6, 5...Be7, and 6.O-O winds up like the Classical Dutch or English Opening (depending on whether White plays d4 or d3), while 3...Nf6 4.e3 g6 5.Nf3 Bg7 ends up an English or Kings Indian depending on d3 or d4 by White.

1.b4 d5 2.Bb2 Nf6 3.e3 e6 4.Nf3 followed by 5.c4 or 5.a3 and 6.c4 winds up a Reti. You can also get some Queen's Gambit type positions.

1.b4 e5 2.Bb2 f6 often leads to a reverse French up 2 tempi. 3.b5 d5 4.e3 Be6 5.d4 e4 and you can see where this is going. Black will have to play f6-f5 at some point, whereas White usually plays f4 in 1 move. So going first and f7-f6-f5 gains White 2 tempting (namely the pawn on b5 instead of b2).

And yet, many don't think of the Sokolsky in terms of the English, Reti, QGD, Reverse London, King's Indian, or Reverse French. Only the Exchange Variation is its own like with no real similarity to other openings.

There is no best opening. The best opening is the one you understand best yourself amongst a FINITE number of good options.

This is COMPLETELY the wrong approach and VERY BAD ADVICE since we have access to statistics and can come to rational conclusions on how likely a random opponent is to know a line... if you took this advice you'd be left with almost no element of surprise in your play, you will just neuter your repertoire due to imaginary concerns. But you don't even believe this advice because you play 1. b4, which is not an ideal theoretical line anyway.

It does depend on the setting - if your opponent can prep against you that's something different, and you need to play theoretical lines then, but in online games it doesn't work that way.

But I don't think I'd recommend a beginner play a hypermodern opening either.

Really I like to play fighting openings that give you opportunities to surprise the opponent, and pressure them early to play correctly, while still being solid. This is why for black I recommend sicilians such as the Four Knights, Classical, Accelerated Dragon, or Taimanov... and then vs d4 the QGA or the Slav.

As white play e4 or d4. You can branch out into strange moves as white later on, but for now just learn the core of chess which is e4/d4. You need to understand e4/d4 to understand the transpositions of other moves.

For e4.... play the italian, some anti-sicilians, vs. the french I'd recommend Nc3, and vs the kann go with the tal variation or the fantasy.

The open sicilian is something you have to work up to playing, you'll get owned otherwise. And it's alot of theory. For an anti-sicilian.... I'd recommend trying 2. b3.

In the french Nc3 tends to be more tactical, but I find it just works. Also I almost never run into the winawer, I don't really know why since it's clearly a great line but people aren't playing it. But against the winawer I'd recommend playing a sideline early on, avoiding the main line. Otherwise I think black will just have a superior theoretical knowledge and will just win.

Beginners would need something strategically simple. While they learn their middlegame and endgame abilities. A beginner won't yet know what middlegame positions work best for them and be able to head for them. Last century, "Play Better Chess" (Barden) was a good staple for beginners on openings and much more. I am many a long year out of touch. What is the modern equivalent? C'mon the hive mind. Let's lay aside our own opening predilections and think like a trainer here. For White, I would still suggest 1.e4 (2. Bc4 avoiding the Petrov and Latvian and intending 3. Nf3 Giuoco Piano), 2. Nc3 Sicilian, Exchange French and Caro Kann) and as Black 1. e4, d5; 2. ed, Qxd5; 3. Nc3, Qe8 (not theoretically best by any means but solid, and the problem with 1. e4, e5 for Black is that there are all sorts of strategically complex second moves for White as well ascthe "standard" 2. Nf3), 1. d4 or 1. c4 symmetrical response move 1 then go looking for what nuances suit you.

For me, it's the Danish Gambit.
Let me elaborate...

...and these are the moves of the Danish Gambit - Two pawns accepted

After the second position, we have a superior bishop pair on b2 and c4 aiming to attack, also, our queen can move anywhere and after developing the knight to f3, we can castle to safety — by move 7. I like to play in this position as white because we have a (positional) advantage just from the opening! 
There are a lot of variations of the Danish Gambit so it's fun to explore.
I hope this helps.