Horizon ZD, need help

Total buyers remorse... I don't get this game, or it's too hard although I play on easy, or it's just not my cup of tea. The graphics are great.

So I played like 1%, have a horse and then there's this big bird in the sky, where I have to cross that bridge. I already have had a super hard time with all those dinos constantly attacking me, aiming for the tiny weak points while they run me over, but somehow I managed to do so until now. But this bird? No chance for me. I tried about 20 times and it's super frustrating. I aim, I hit somewhere, nothing happens, I'm dead again. Which of the 1000 weapons, ammo, armor, potions do I have to buy? Oh damn this RPG shit. Am I the only one? I'm close to put this game to rest, although yeah good graphics. So frustrating!