Welcome @isabelle_miserani
For this analysis, you could use the tools directly if you want to. Some potential tutorials for follow are here → Galaxy Training!. If you had a tool in mind, check the form since more tutorials will be linked there, plus you can search that site directly. This would avoid the need to create the artifacts.
However, if you still want to use the Qiime/Qiime2 tools instead, you can get your artifact organized by putting the data into a collection. The reads will need to have the original sequencing identifiers. Then you input to the import tool, and proceed to downstream tools.
This topic here has the links to the resources we have:
To inspect artifacts, you will need to download the file then upload to the site hosted by the original authors. This is another good topic since one of the authors was helping.
Hope this helps to get you started, and we can follow up more! 