So is it true that the sun will eventually crash into the earth if so that’s just scary

Yes.

Explanation:

All stars have a life cycle, meaning they eventually burn out and die. Currently, the Sun is in its "main sequence" phase, meaning it's fusing hydrogen into helium in its core. Then, it'll eventually be in the "Red Giant" phase. During this phase, the Sun has begun thermonuclear fusion of hydrogen in a shell enveloping the core. Then, it'll multiply its radii multiple times, and the Sun will eventually engulf the Earth.

the core of the sun is so hot and there is so much pressure, nuclear fusion takes place, hydrogen is changed to helium. nuclear fusion creates heat and photons. when the heat reaches the earth it warms the molecules of the atmosphere, and they warm other molecules and so on.