I am currently writing my first research paper and have decided on a journal to target. I have a problem in the referencing style, since the guide of author is giving examples in one way (for e.g. they do the year of publication in brackets), but the papers in the latest issues have references in a different format (e.g. year of publication not in brackets). Which would you follow in submission? Or is it not that important? I just follow one way and then if they want the other style I change it later on? Thank you

I'd follow the guidelines for authors. But if in doubt you could email the editor to ask.

You should be able to access the house style rules for contributors in both the hardcopy and online version of the journal. But I agree if in doubt contact the editor. As far as I know it's important not to embed your formatting (in cement!!) so much that it could present a problem bieng re-formatted.