There is no specific proof for the actual big bang but if you look about information on CBR ( cosmic background radiation ) it is a type of backup that the universe started from not from one massive big bang, but from millions of big bangs together, also as for what was there before the big bang, there was nothing but a few different types of particles, which eventually fused together.

To do with the universe being infinite there isn't much proof as no one knows how big the universe actually is, but the red shift theory tries to prove that the universe does not have an end and in fact is still expanding.

please don't quote me word for word I'm not an expert on space or anything but if I'm wrong please correct me.

Because all other planets and stars in the universe are constantly moving away from us in all directions. If you were to rewind that all planets and stars would meet at one point in a group. "The Big Bang" makes all planets and stars move away from us and therefore (in my opinion) provides enough evidence that there was a big bang.

P.S Learnt this at school today

*Cosmic-Radiation in the background.

*The Red Shifting of Stars.

*The Higgs Boson Particle.

I'll not go into detail since it will get closed but anyways it's a theory but there is a lot of hard evidence to support it.
Google it if you want more information on it.

We can prove the Universe expanded from nothing, or at least an infinitesimally small point.

We know the Universe is expanding, due to being able to observe the red shift of galaxies, a phenomena I have observed myself.

And due to this expansion, we can model this and reverse the process using very powerful computers. This is how we know that the Universe is 13.77 billion years old, due to the fact that we can backtrack the expansion of our Universe.

XxEpIcDuStXx wrote So people say the big bang caused the universe, but how can you prove the big bang happened and how could you ever, what was before the big bang? Which is why I now believe that the universe was always there and always has been probably for billions of years thats why its infinite, but we have not realised this yet, if you think about it, its is infinite so there is nor a start or a end!

The Universe isn't infinite they say it's growing.. If something is still growing that means it's not infinite so therefore your theory isn't 100% correct.

na i disagree theres so much proof of the big bang and the only theory that makes sense

the big bang is a repeative thing. it takes billions of years, but the big bang occurs, then when it reaches its farthest distance from its explosion, it will slowly start coming back together, then explode again.

of course its not been proven that's why its called The Big Band 'THEORY'

dNikzeh wrote I think 2030 we all going to die in a way. People said in 2012 we all going to die by the Sun dropping into the Earth. It all rumours we can not tell what's going to happen, unless it does happen.

Can't happen, we revolve around the sun, not the other way around. While we are revolving we are millimeter by millimeter moving away from the sun, so in truth it is far more plausible that our planet would freeze before "The sun drops into the earth."