To begin with, I’m going to caveat your question in several ways.

Firstly, ‘literal’ is a problematic category in my view. Particularly since you define it as “6 day creation”, which reflects a very 20th century Anglosphere (and American in particular) set of debates. ‘Literal’ in modern hermeneutic debates is really a codeword that religious conservatives use to mean “takes the Bible seriously”, and religious liberals use to mean “is fundamentalist”. Neither of which is really going to move forward an understanding of interpretive practices.

The second problem with the label ‘literal’ is that almost no-one interprets Biblical literature ‘literally’ (except possibly I will grant some early North African Christians). What’s ‘non-literally’? That’s the can of worms – because every interpreter on the ‘literal’ end of the spectrum is making a significant use of a range of figurative uses of language that span from simple turns of phrase through to full blown philosophical allegory.

The second caveat is that the bulk of our evidence for early Christian interpretation is documentary, and this reflects writers, not ‘everyday Christians’ in Antiquity (who may have been readers, but we are only getting writers’ opinions; on the whole, Christian rates of literacy were probably marginally higher than non-Christian rates, but still relatively low compared to modern societies with theoretically-universal education).

Which brings me to the third caveat, and that is that the 2nd century isn’t a period in which we have a lot of commentary going on. So I’m going to push out the boundaries of your question chronologically.

In the Fragments of Papias (ca 110-140) we have a comment in 12, where he says, “those ancient and earliest interpreters who agree with each other in understanding the whole ‘six days’ to refer to Christ and the Church.”

This suggests a typological reading of understanding the Creation account to have a figurative relationship and spiritual meaning. But, I should caution, this doesn’t necessarily mean that they thought it wasn’t at the same time a literal six days (it might, it just doesn’t prove it. I.e., I’m cautioning you against reading figurative meanings as meaning the literal isn’t relevant or true in the interpreter’s understanding).

Ephrem the Syrian, writing mid 4th century, is quite clear that the days are not allegorical, “So let no one think that there is anything allegorical in the works of the six days. No one can rightly say that the things pertaining to these days were symbolic, nor can one say that they were meaningless names or that other things were symbolized for us by their names. Rather, let us know in just what manner heaven and earth were created in the beginning. They were truly heaven and earth. There was no other thing signified by the names “heaven” and “earth.” The rest of the works and things made that followed were not meaningless significations either, for the substances of their natures correspond to what their names signify. Commentary on Genesis 1.1.

Other 4th-5th century authors, Basil of Caesarea, Augustine, I would say spend time explaining the ‘physical’ reality of what’s going on through Genesis 1, but without assuming that this precludes any ‘spiritual’ meaning. Basil, too, can make clear statements against ‘allegory’, as he does commenting on the grass in 1:12, and insisting that it is ‘grass’, summing up, “Therefore, let it be understood as it has been written” (Basil, Hexaemeron 9.1) But, this doesn’t stop other authors from making spiritual or allegorical connections between Creation and spiritual themes, as for example Origen (writing early 3rd century) does. He, for instance, suggests that the division of water from dry land in verses 9-10 possibly symbolizes the separation of sins and vices from the body.

So, how to summarise? I would say there existed alternate interpretative traditions in the early church, some of which were prone to more exaggerated allegorisation and ‘spiritual interpretation’, some of which were well-inclined away from such interpretations but still were not, in the modern sense, ‘literalists’. Even the literalists in the early church find spiritual meaning in the Genesis narrative, they just have a more ‘restrained’ way of reading it. It’s difficult to establish what average Joe Christian thinks in the 2nd century, because while the documentary evidence is rich, it’s not rich enough to establish that kind of detail.

We know very little about what early Christians believed because most of what survives about them was recorded by Roman historians, who themselves express distaste and confess to knowing little about early Christians.

Early Christians would learn the story of Genesis through the Septuagint, translation of the Hebrew bible into Greek, which eventually became part of the Old Testament canon. But to my knowledge, the earliest bibles incorporating the Septuagint were from the 4th century, 200 years too late for your question.

I don't think Christianity in the 2nd century had a universally agreed upon canon, which would be needed to really answer your question properly.