The main differences are in the visual presentation and some minor tweaks in character expressions. But the core story and plot remain largely the same.
The Haikyu anime follows the manga pretty closely. There are only a few tweaks here and there for better animation or to make it more suitable for the screen, but the essence remains the same.
The Haikyu anime adheres closely to the manga. The characters' personalities, the key events, and the overall tone are all preserved. Though there are a few changes here and there, they don't significantly deviate from the manga's essence.
Well, you could start from the volume right after where the anime ended. But also, it might be helpful to go back a bit to get fully immersed in the story again and catch any details you might have missed before.
The main differences are few. The anime might simplify some complex panels or add a bit more drama for visual impact, but the core story remains the same.
The ending of the Haikyu manga sees the main characters having accomplished their goals and leaving a lasting impact on the volleyball world. It wraps up their stories in a satisfying way.