I've made a map of local archaeological sites using Google Maps (with custom layers) for a local museum. In trying to get it printed, we've decided it would be better to transfer it to QGIS. There are OS map tiles available for the area, and I have all the data already on Google Maps. I just have no idea how to transfer it. Don't even know where to begin apart from in the help section and this forum.
I have downloaded both OS map tiles, and I currently have QGIS 3.16 32 bit version.