Is there any magazine (or some other such place) where university students can publish a GIS/Geo related article freely (in English or French)?
PLOS ONE Geographic Information Systems is an open access peer-reviewed journal that may meet your needs. You can find publication criteria here. The beauty of this publication is that it is available freely to the public, which has wide implications for scientific research.
Everyone can freely access and download all PLOS ONE articles without paying subscription fees, pay-per-view charges, or any other restrictions. Publishing open access makes it easier for others to access your research, and it may also help you comply with your funder's policies regarding open access publication and indexing/archiving.
it depends on what you mean by "freely":
You can publish your article also as a student in every paper you like as it will go through the publication/review process like all the other papers. It will be for free for the author.
Try to find a professor who will support you and review your article beforehand: It will be probably easier for you to get into a magazine with the support of a professor.
Also conferences are a good starting point to have the possibility to publish things.
But like ThomasG77 mentioned: you can publish your things on my blog digital-geography.com where we have an English and a French section...