Thoughts are to life, what life is to matter, an increase in complexity.

Much in the way the homo sapien body consists of millions of systems within organs and cells, the large brain we have unlocked our greatest advantage, abstract thought. Animals can hunt, but we can hunt with far greater complexity, and yet for thousands of years our progress was slow and uneven around the globe. The big "boom" periods came with society in agriculture, industrialization, and now the modern communication era. We use ratcheting knowledge to build and communication through language to rapidly increase our capacity.

It may seem circular in nature, but we consider these questions because of our nature as humans. It is possible an alien life somewhere in the galaxy exists and simply ignores notions of philosophy and meaning. We won't know until we have comparable complex sentient species to contrast ourselves against.

Imagine the universe is a ball. Everything in that ball is in the universe, and everything in the universe exists. So we exist because we are inside the universe (that's what I like to think). Now, what is outside that ball? Idk, maybe nothing, maybe the ball is in a room with more balls (multiverse).
Why does the universe exist? Dang dude, ask whoever made the Big Bang. God is a smart fella, he should know
If you're ever in doubt tho, the answer is 42.

Hmm, so is it a moving ball, or a static ball? Or is it in infinite ball? If so, is it really a ball?

The question of what existence is, is an important one but the bigger question is what is consciousness and sentience?
That is the 64K dollars question my friend.
Personally I am a believer of the Anthropic Principle. I think the universe exists to allow consciousness to eventually rise. Not just us humans but all other forms of consciousness and sentience that we don't know about and who must exist all over the universe. Now the other big question is why consciousness exists? To what end?

Don't want to mix in, I have no eggs in this basket but God would not have a gender or sex, since a timeless immortal omnipotent being wouldn't need genitals.

But what about gender identity? Can God choose which gender to self-identity as?

Correct. But since humans need to imagine there is a God to justify their existence, they made him at their image and since males are seen as the dominant sex, humans picture God as being a guy. It's all nonsense of course, there is no such thing as God, outside of humans' imagination that is.

We all adhere to the Universal Law, whether or not we are real or virtual. Ultimately, all existence is bound by those laws, but our experience of them may be a conditional simulation. With regards to divinity, the existence of a god or gods is a choice: either there was always something or everything came into existence. If a divinity was always here and created everything or if it spontaneously manifested itself is another side of the same coin. We really are left to choose our own creator and its origin story.

Existence itself is ultimately a frame of reference: within this relative frame, we are real. Other reference frames may prove that ours is only visible through the prism of another. Your thoughts have physical mechanism and manifestations, but their conjuring is an exercise in creating another frame. We have a deep understanding of what we know to be real, but nothing can be excluded.

That's complicated, but no, it's not literally a "ball"

The universe is expanding, which makes no sense. But (to keep it in line with my last analogy), think of it like a balloon. A balloon that never explodes (as far as we know). 

One thing that I'm curious about is what happens if you manage to reach the edge of the universe and keep going forward. It's physically impossible, since you would need to travel faster than the speed of light, but what if? According to Stephen Hawking (or what I understood from him, at least), you would just keep going around. Like the Earth, it doesn't have edges, so if you keep moving forward you would just keep going around the Earth.

Another problem is dimensions. Where is up or down in space? What is forward? The universe doesn't have a center (because every point works like a center. As in, if we say the Earth is the center, then the expansion started from the Earth. But some science stuff (radiation or something) proved that everywhere in the universe can be "the center")

But anyway, I'm looking at this in the scientific way! We exist for no reason and all at the same time. If we want to give ourselves significance, we will, but ultimately we don't have to. The universe will keep expanding, stars will die, civilizations will rise, regardless there being a reason.

My opinion is that we humans tend to humanize the unknown. God, Gods, Aliens. We all seem to imagine them in our own image IE: gender, sex, a body, two eyes, two arms, two legs etc.