The sun is much much bigger than the Earth. It only looks small because it is very far away. It is, without a doubt, the biggest thing you have ever seen up close.
If we took the Sun and put it on one side of a teeter-totter, we would have to fill a huge barrel with 300,000 Earths to raise both sides of the teeter-totter up into the air.
This is very hard to imagine. Think about 300,000 times all the buildings, mountains, people, cars, trains, oceans, rivers and the heavy thick rocks under your feet.
And our sun is not the biggest star either. There are stars much bigger than our sun.