Short answers, pulled from the story.
The Solar System is the gravitationally bound system of the Sun and the masses that orbit it. The Sun holds 99.86% of the total mass, the four giant planets account for 99% of the remainder, and everything else including the terrestrial planets, dwarf planets, moons, asteroids, and comets together makes up less than 0.002% of the total mass.
The Solar System formed at least 4.568 billion years ago, when a dense region within a large molecular cloud collapsed under gravity. The collapse created the Sun and a protoplanetary disc, and the planets assembled from that disc through accretion as dust and gas coalesced into ever larger bodies.
The eight planets in order from the Sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Mercury, Venus, Earth, and Mars are terrestrial planets, Jupiter and Saturn are gas giants, and Uranus and Neptune are ice giants.
Planets dominate the orbits they occupy, while dwarf planets are objects of planetary mass that orbit the Sun directly but do not dominate their orbit. Ceres in the asteroid belt and Pluto, Haumea, Makemake, and Eris beyond Neptune are among the recognized dwarf planets.
The Solar System extends to the edge of the Sun's Hill sphere, where its gravitational potential becomes equal to the galactic potential, at 178,000 to 227,000 AU. The theorized Oort cloud, a spherical shell of up to a trillion icy objects, is thought to reach up to around 200,000 AU from the Sun.
Roughly 5 billion years from now the hydrogen in the Sun's core will be entirely converted to helium, ending its main-sequence life. The Sun will expand to roughly 260 times its current diameter and become a red giant, vaporizing Mercury and Venus and rendering Earth and Mars uninhabitable, before ejecting its outer layers and leaving behind a dense white dwarf.