help me find a good opening

Finding what opening is best for other people won't help you one iota. No 2 people think alike.

There are 4 sound responses to 1.e4 and 4 sound responses to 1.d4 along with 4 best moves for White on move 1. What works best for one may not work best for someone else.

While yes, there are players that play 1.b3, 1.b4 (myself many times), 1.Nc3, 1.f4, etc, there are clearly 4 superior moves for White over the other 16.

They are, in no particular order, 1.e4, 1.d4, .c4, and 1.Nf3

For Black against 1.e4, they are 1...e5, 1...e6, 1...c5, and 1...c6

For Black against 1.d4, they are 1...d5, 1...e6, 1...Nf6, and 1...f5.

Now "technically", Black could play 1...c6, but only if followed up by 2...d5, transposing to the Slav (or Slav-type setup against 2.Nf3) or Caro-Kann, depending on White's second move. This is different from 1...e6, where yes, transpositions to the French, QGD, Nimzo-Indian, and Dutch are possible, there are independent lines too, like 1.d4 e6 2.c4 Bb4+, hence why 1...e6 is included in that list but not 1...c6 as the latter will always transpose if Black plays soundly while the former may or may not transpose.

But the main point is that what works best for one might not work best for someone else.

I personally play 1.d4 (with the occasional 1.c4 or 1.Nf3) as White, 1...e5 or 1...e6 against 1.e4, and 1...e6 against 1.d4. That does not make those the best responses for you just because they work best for me.

There are a FINITE number of "best moves", but what is best for one person may not be best for somebody else.

If someone told me they thought 1...c5 was their best move against 1.e4, I wouldn't argue with them. If someone else said 1...c6, no argument. Someone says 1...b6, now I will put my foot down and say you are wrong.

I would also say you are wrong if you said 1...c5 was THE BEST and that it was superior to 1...e5, 1...e6, or 1...c6. That would be like saying that one of four different denominations of Christianity was superior over the other 3. Like religion, your view of one of the "big four" is superior over the other 3 is STRICTLY A BELIEF as there is no proven fact that say, the Caro-Kann is superior to the Sicilian or vice versa, and before you go spewing statistics, you are likely factoring in games with massive rating differences, games from before theory was well established, etc. Now you might argue "but I only factor in master games". Yes, but if White is 2700 and Black is 2550, they are both masters, but that game will be won more by White than black no matter the opening, and if 2700s happen to be playing the Sicilian and 2550s are playing the Caro-Kann, the numbers will be skewed.

All 4 responses to e4 are equally sound, and each have gone through their wave of popularity due to waves of former world champions.

The French was extremely popular in the 3rd quarter of the 20th century with the likes of Petrosian, Botvinnik, Uhlmann, Geller, etc.

The Caro-Kann was popular in the 70s and early 80s with Botvinnik and Petrosian using it in their older years along with Karpov.

The Siciian Najdorf and Scheveningen had it's hey day with Kasparov as world championship from 1985 to 2000.

Then it was all about the Berlin in the 2000s with Kramnik on top.

Now the focus has shifted to the Sveshnikov and Rossolimo Sicilians mostly due to the Carlsen era. You also see some dabbing at openings that Carlsen's challengers and post Carlsen players coming back to fruition. From Ding Liren's French to Caruana's Petroff.

But notice all of these involve answering 1.e4 with either 1...e5, 1...e6, 1...c5, or 1...c6.

So the "best openings" are FINITE, but there is no one opening that is superior to the others.