Hello
I will quickly show you how to add a BaseMap to QGIS without installing any plugin.
1. you have to find a website where you can get the URLs for the basemaps. I will use this as example: https://leaflet-extras.github.io/leaflet-providers/preview/
2. choose the layer you want and copy the URL. For example, I will use ESRI World Imagery: https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}
3. in the Navigator window of QGIS, look for "XYZ Tiles"
4. Right click > New Connection
5. set a Name of your choice
6. pase the URL you got from step 2 into the URL text field
7. once it appears under the section "XYZ Tiles" you can add it to the map as any other layer
You can see a video of the process here: https://www.youtube.com/watch?v=3j8UaOYC-0A
Thank you for reading. Leave your comments in the comments sections
