How to play as black against the Birds opening??

#7
I would play g5 with the threat of g4 and not Nf6 on Nf3

Wait, I made a study for the simple 1. ... d5.

Bird Opening: Horsefly Defense

i cannot understand why stockfish says nh6 is equal . f4 nh6 = according to stockfish

That the opponent has a pawn more is quite possible. But that is also the purpose of a gambit. Black has quite a lot of room for that :)
The variation you publish may be the main variation. But it is deadly boring. Based on the Lichess rating, I would say that we have a maximum of 1650 Fide Elo here. Except for the CM.
If you take a look at the database, you will see that it is a normal distribution. 1933 games can be presented as meaningful.
Take a look. www.365chess.com/eco/A02_Bird_From_gambit

When I go to a tournament, I want to play chess and not play old books. And the most important thing is that we are all not engines. We make so many mistakes. A rating of 0.5 is worth nothing.

Suprisingly mvl played this lichess.org/uAOWpVZ9#9

Continuing on From's gambit-
Black actually gets the compensation for the pawn later on, given that black knows how to continue
For e.g:
1. f4 e5 2. fxe5 d6 3. exd6 Bxd6 4. Nf3 g5
5. g3 g4 6. Nd4 h5 7. Nb5 h4 8. Nxd6+ Qxd6
9. Nc3 Bf5 10. gxh4

If you play the From be sure you can handle the King‘s gambit, 2.e4!?.

You have been warned^^

Never analysed it and its probably bad but 1...e5! would be interesting

oh apparently its fine - if u wanted to surprise them it might be valid