I personally believe in evolution, and I think the universe began with something like this...
The universe began as
nothing. The boundary between turbulence and order (I think) was all
that was anywhere. Anything could happen, so a small sea of particles
formed. Around this sea formed a group of black holes. These sucked in
the particles and spit them out in white holes (black hole-white hole
theory is real, just can't remember its name, sadly). The universe began
in many points all at once. The white holes formed at a static distance
from the sea, forming a sphere. these particles flew outwards in every
direction, forming the base of our universe. These particles bonded and
ripped apart and bonded again. Again, and again, and again.
A large hunk of molten rock draws smaller hunks of
molten rock to it, adding to its mass. A small ball of gas is lit and
starts combusting. The gas ball grows and the molten rock hunk is drawn
into orbit. It orbits it for a while until something unexpected happens:
it begins to cool. the small gas ball fails and is snuffed out. The
somewhat cooled planet shoots forward, propelled by the previous orbit.
Gasses collect in this planet's orbit and form a thin atmosphere. Over
time enough gasses collect and a cloud-like shape of denser gas forms. A
charge builds between the ground and gas until a lightning bolt goes
off, giving the power to chemically form water. This process repeats for
years. This planet nears the orbit of a sun and collides with a planet,
its water supply cooling it rapidly before flying into orbit. This
newly cooled planet with its new atmosphere begins to form clouds and
lightning. One day a chemical reaction fueled by lightning formed a
protein pool. A lipid pool formed under similar circumstances. All the
components to a simple prokaryote formed and small bits got into a small group. That's where life started, fueled by that final bolt.
EVENTUALLY,
it became a smarter cell. It eventually formed a primitive RNA and
formed some crappy DNA. Many MANY MANY MAANY thousands of years later
enough accidental mutations with the crap cell dying out and starting
over made it smart enough to produce more advanced membrane-bound organelles.
Your biology class probably explained the rest. Enjoy!