The creation of comets How are comet and meteors made, and what causes them to travel through space so fast? I have tried researching, but I decided this was the faster way.
Comet Formation
From Altweg et al., Fred Whipple first came up with the idea of comets being &quot;dirty snowballs&quot; and Oort came up with the idea that comets originated in a very distant cloud around the Sun (now aptly called the Oort cloud).  Matter in the cloud gradually came together through gravity and other processes to form comets.  Now we know some comets also come from the Kuiper belt.
Comets are incredibly important in astronomy because they contain pristine matter from the early formation of the galaxy through the accretion of the protoplanetary disk, as shown in this illustration, also from Altweg et al.

More recent space mission analysis of comets has caused the community to more accurately refer to comets as &quot;icy dirtballs.&quot;
Asteroid Formation
Asteroids are not as old as comets in some sense since, according to Raymond and Nesvorny:

The asteroid belt was dynamically shaped during and after planet formation.

The asteroids can differ much more significantly from one another than the comets.  Raymond and Nesvorny go on to say:

A number of processes may have implanted asteroids from different
regions of the Solar System, dynamically removed them, and excited
their orbits. During the gaseous disk phase these include the effects
of giant planet growth and migration and sweeping secular resonances.
After the gaseous disk phase these include scattering from resident
planetary embryos, chaos in the giant planets' orbits, the giant
planet instability, and long-term dynamical evolution.

Here is a cartoon from their paper comparing and contrasting three competing solar system development models for the creation of the asteroid belt:

Why do comets and meteors move so fast?
Comets are very slow moving until they get bumped into eccentric orbits with the Sun.  When we see them from Earth, they are moving at near their fastest speeds as they pass closest to the Sun, as an example of Kepler's 2nd law.
Meteors and meteorites are mostly moving around the sun at similar speeds as Earth before colliding, but in somewhat different directions.  This makes it appear that they are travelling very fast indeed with respect to the Earth as they enter the atmosphere.  In addition, they are sped up by Earth's gravitational pull.