If there were only one type …

Well for starters, we wouldn’t exist. All like charges means that chemical bonds will be unable to form, which means that the elements (which wouldn’t actually be elements anymore because the atoms that they consist of won’t have a balance of positive and negative charges) that make us up won’t be able to, well, make us up. Also, there’s the problem with intermolecular forces. Not only would molecules be able to form, but no complex structure of any kind. If everything that would otherwise have a negative/positive charge had the opposite and all matter had like charges, then they wouldn’t be able to get near to each other. Instead, I’d reckon (this is a wild guess after mere seconds of speculation) that most of the matter would be relatively uniformly distributed across the universe. Unfortunately, I can’t say much about antimatter. Following the Big Bang, it is theorized that there might be some sort of process that favoured matter over antimatter, which would explain why they are so disproportionate in abundance. However, if there existed both matter and antimatter of only one charge, then (given my knowledge) it would be fairly difficult to judge which one would have been produced