Our first steps tour and our frequently asked questions will help you a lot after registration. They explain how to customize the interface (for example the language), how to upload files and our basic licensing policy (Wikimedia Commons only accepts free content). You don't need technical skills in order to contribute here. Be bold contributing here and assume good faith for the intentions of others. This is a wiki — it is really easy.
There seems to be a problem regarding the description and/or licensing of this particular file. It has been found that you've added in the image's description only a Template that's not a license and although it provides useful information about the image, it's not a valid license. Could you please resolve this problem, adding the license in the image linked above? You can edit the description page and change the text. Uploading a new version of the file does not change the description of the file. This page may give you more hints on which license to choose. Thank you.