What would have happened to the earth if the sun were significantly larger than it is?

Well, sweet pea, if the sun were significantly larger than it is now, Earth would get toasted faster than a marshmallow on a summer BBQ. The increased size would also result in a stronger gravitational pull, leading to some intense tidal forces and potentially disrupting our cozy little planet. So, long story short, we'd be fried and flung into space like a cosmic Frisbee.