Hello,
The Sun is not hotter in the summer. The energy output of the Sun does not depend upon the seasons on Earth. The seasons also are not caused by the Earth moving closer or further away from the Sun as it orbits around the Sun. The real reason we have seasons is that the Earth's rotational axis is tilted at an angle relative to its orbital plane. As the Earth orbits the Sun, sometimes the northern hemisphere is tilted towards the Sun so that the Sun's rays shine more directly on it, which we call summer. In winter, the northern hemisphere is tilted away from the Sun. The seasons are opposite in the southern hemisphere. There are some drawings here showing how this works.
https://spaceplace.nasa.gov/seasons/en/ Kris