I have several layers/maps in QGIS Girona 3.0 version and I'm thinking about uploading to Pi version 3.14.
Would I be able to keep using the same files in the new version?
All QGIS Projects (.qgs and .qgz) are compatible between QGIS versions, so you don't have any problem in upgrading from 3 to 3.14. The data (.shp, .tif, etc.) are independent from the GIS software. All these data format are OGC standards, so you can use them with any GIS software and, of course, with any QGIS version.