There are tons of pagan religions, of which Wicca is just one, all with varying beliefs and practice. No one pagan can answer for all others, never mind one Wiccan answering for all others.
There is no set belief among all Wiccans on this subject, but I'd say the majority would go with the scientific explanations. I understand that before we knew the science behind how the earth and the sun and the moon, etc. work, that stories were told by people about the gods in order to explain these mysteries, and I respect the various cultural creation myths.
Honestly, does it really matter? I am here now so I might as well do something worthwhile with this life of mine.
Which pagan religion? there isn't just one. You would have to look each one up to find that out. Norse, Celt, Egyptian, Roman, Greek, Middle Eastern/ Babylon, etc.....
But I can honestly say I haven't met a pagan yet that has read the creation myths of their respective paths and believed in the story literally.
Science does not state Evolution CREATED the earth and other planets. Evolution is something that happened after the earth was already here and all of the material needed for such was already here.
Personally, I would have to say, I Don't Know what or how the earth was created. I honestly don't worry about it. It doesn't do any good to even argue the topic as No One Knows..... many people have opinions about it, many have beliefs about it.... but no one really knows. And life is much simpler if you just say "I don't know". =)
There are numerous myths out there that are somewhat accepted as the explanation of the creation of the universe, however, most Wiccans and Pagans accept the traditional scientifically based ideas of evolution and the Big Bang.
There is not one religion that is called 'Pagan'. It is a term originally used to describe non-Jews and non-Christians, but the category now often includes non-Muslims as well (as they are all Abrahamic religions). So 'Pagan' is a term that could be used to describe different religions, Wicca being one of them.
There are literally hundreds or even thousands of different cultures and spiritual traditions that could be called 'Pagan', including (but not limited to): Aztec, Maya, Norse/Saxon/Germanic (Asatru), Greek (Hellenic), Roman (Religio Romana), Celtic, Slavic, Russian, Egyptian (Kemetic), Babylonian, Sumerian, Arabian, Canaanite (Qadish), Vodoun and various African traditions, various Native American shamanism, Mongolian shamanism, Korean shamanism, Tibetan (Bonism), Indian (Hindu), Japanese (Shinto), Chinese (Tao, Shen), Finnish, Vietnamese, Thai, Turkish, Scythian. There are many more. As far as I am aware, ALL of these traditions currently have at least some followers (so they are not 'dead' like many people think they are). Also, some traditions such as Hindu, Taoist, Shinto, Native American, Vodoun, and various others may not like the term 'Pagan' as it originated as an offensive term to describe non-Christians (and still is often used that way by Christians towards Hindus/Shintoists etc. in Asia). Also, Asataru, Hellenism and several others *may* dislike the term as well.
In my own tradition (Canaanite) the creation story is basically a cosmology. Wind mixes with Desire to form the cosmic egg, and from it emerged the primal Depths and Mountains. The gods were born to Guruma-wa-Tahamatu (Mountains-and-Depths), and Shamuma-wa-Artzu (Heaven-and-Earth). From there, El took control and basically he and Asherah gave birth to the other gods (after overthrowing their parents and creating the universe from them), and they place the firmament in the sky, cause the plants to grow, create animals and people etc. Baal commands the waters to flee from the earth and becomes king of the gods. They then order the planets and the number of days and months, and found the first cities on the earth (including Byblos/Gubla, considered to have been founded by El in Canaanite legend, and is in fact one of the oldest cities in the world).
I don't take the creation literally however, though it does give a helpful overview of the Canaanite view of cosmology and our role in the universe and with the divine etc. It is just a story, though it does have some helpful things that we could view as having parallels with modern science (or not contradicting it at least), such as Wind and Desire mixing to form the universe, order emerging from chaos, the gods (natural forces personified as beings) creating humans with a sense of awe to bow down and revere the natural forces that keep them alive.
Most people would agree with modern science, as we worship gods of natural forces it would make sense for them not to contradict natural sciences in any way (also we don't have to take epics and legends literally).
Pagan is a category that many, many religions fall under and they don't necessarily share a lot of beliefs.
I'm Wiccan (one of many Pagan religions)... we have liturgy and we have myth, not scripture; I believe there is a Higher Power, but I have no idea about matters of divinity-- are the Gods creators, or part of the universe? if creators, how was it done? how does it work? I don't know and frankly my religion doesn't focus on that, it focuses on how I live the life I have.
I have no reason to dispute scientific findings like evolution, or the big bang, Agnese's, etc...
I believe we are here just to live... I don't believe there is fate or a divine plan for everyone. Life just is, and it is what we make of it.
The majority of pagans view creation myths as just that, MYTHS. We now have a scientific explanation for the origin of the universe. This does not belittle the stories but they are metaphors. Most pagan seek to understand the world they live in and science gives us a means to do that.
I don't know about other pagan religions (there are many, pagan and Wiccan aren't the same thing), but I know that Wicca does not have a creation myth. I personally, turn to science to fill in the gaps where my religion fails to explain things and I turn to my faith to explain things that science either has yet to figure out or doesn't take seriously.