Yes, if you are standing on Earth's surface and looking straight up into space, you would not be able to see Earth's curve directly. The curve of the Earth becomes apparent when you observe the horizon or look at distant objects from a vantage point. However, when you look straight up into the sky, your line of sight is perpendicular to the surface of the Earth, and therefore, you would not have a direct view of the Earth's curve.
From the perspective of an observer on the ground, the sky appears as a hemisphere above them, gradually fading from a bright blue near the horizon to a darker shade as you look higher. This perception is due to the scattering of sunlight by the Earth's atmosphere. But you would not be able to perceive the curvature of the Earth itself just by looking straight up.