Our solar system (Heliocentric) began with a Nebula. Nebulas are clouds of interstellar dust and gas.
Something disturbed the Nebula, and it collapsed unto itself, under its own gravity. It shrinks and heats up, compressing in its center.
The matter around the center begins spinning around, and flattens into a disk called an accretion disk.
A protostar forms in the middle of the accretion disk, otherwise called Protoplanetary disk and it will eventually become a star. Our Sun is a Main Sequence Star.
Planetesimals, clumps of matter, are also formed by accretion. As they grow they become objects called protoplanets, which will then evolve into actual planets
In the solar system, there are Terrestrial and Jovian planets. The 3 planets closest to the Sun are Terrestrial, the rest are Jovian. Jovian planets are large gaseous planets, Terrestrial planets are rocky and solid. Our Solar system was formed 4.6 billion years ago