Here's some questions I would like to see answered from an Evolutionist/Big Bang proponent
Your screwed right out of the gate. A person need not accept evolutionary theory to accept bog bang theory and vice versa, They are not the same, nor are they even closely related.
1. How was the universe created? Let's say for a moment the big bang happened. Then where did the galaxies come from?
They didn't "come" from anywhere, they coalesced though gravitational attraction.
What about stars,
Gravatational collapse of stellar gasses.
planets, moons
Accretion discs formed around a hot dense cloud of gasses undergoing the aforementioned gravitational collapse.
nebulas
Clouds of gasses and other debris expelled from a solar system after the aforementioned star exploded taking the aforementioned planets with it.
gravity?
Once again, gravity didn't "come" from anywhere it's a fundemental force, it's part of what our universe is.
If the Big Bang happened, that was a miracle in itself
You assume too much. Just because it's the only bog bang that we know of doesn't mean that it was a singulary unique event. Just because you can't explain something doesn't make it a miracle.
but then to have a galaxy form with stars, planets, moons, etc. would be incredible.
So incredible that it can be reduced to mathematical equations. Give the forces acting on matter in this universe it's highly unlikely that anything else could have happened, hence the reasons these formations are so numerous.
Did all of these happen at the beginning or later on?
Later. Some sooner than others.
2. Let's say evolution is true, where did plants and trees come from? Did they evolve from a lower lifeform?
No. They evoled from other lifeforms, there is no higher or lower forms of life in an evolutionary sense, just less fit or more fit to reproduce in their current enviroment.
What about bacteria and viruses?
What about them?
How is it possible that plants and animals have a symbiotic relationship?
They evoleved together in a particular enviroment and over time became dependent on each other to either feed or reproduce. It's called co-evolution.
Some people theorize that the Earth was formed billions of years ago and was basically a big molten rock that later cooled down
Some very uninformed people might think that it boils down to something that simple... They are wrong, it's much, much more complex than that.
If that's the case where did the Oxygen, Hydrogen, Nitrogen and other gases come from?
It isn't the case. Most of those elements were already present when the planet formed, they didn't "come" from anywhere.
Where did magnetic fields come from?
It's generated by the geomagnetic dynamo that is the result of the rotation of the planets molten iron core.
Where did the water come from
The leading theory is from impact events with Main Belt comets.
why do we have salt water and fresh water?
Erosion
Where did our Moon come from?
Most likely an off center impact with a planetary body slightly smaller than Mars.
Now heres the fun stuff.
It's amazing that a magnetic field is required for us to survive.
How is it possible that our moon is required for our survival?
These things aren't there because we need them to survive, we are here because the right conditions existed for lfe to arise and survive, albeit with the occasional mass extinction.
I don't believe in the Big Bang. In the beginning God created the Heavens and the Earth.
I'm sorry that you cannot accept the universe with all it's majesty without having to think that some magical being created it all just for your benefit. I'm sorry that seem to think that the universe must, by default, revolve around you. I'm sorry that you refuse to see the amazing and intricate ways of the universe without having to invent a magical being that you want to have created it.
I would like to see some of your thoughts on the questions though.
If you are sincere in your search for knowledge, I wish you luck. If you are not, then the world will simply be burdened with yet another science denying idiot with an undeserved superiority complex.