
Daniel B. answered 12/05/21
BSc. in Land Surveying and Mapping and MSc. in Urban and R. Planning
Please elaborate better on what you are trying to do. QGIS as well as any other GIS/Mapping Software may have a "default" coordinate system selected but as a user part of beggining any project you must establish and set the working coordinate system of the project. After you do this, all data you input must be changed or already be in this same coordinate system.
If you can explain exactly what you are trying to do maybe I can help you better.