To Start learning GIS from scratch, you can follow the below steps:

ArcGIS Pro

Start Learning ArcGIS Pro which is a wonderful tool being used for creating feature classes, and analyzing, visualizing, and geoprocessing spatial data. The tool is very powerful that allows users to deal with 2D and 3D Vector data types plus the Raster. GIS beginners use this tool to create polygons, points, and line, feature classes. The tool also allows users to perform some basic and advanced analyses of spatial data.

QGIS

QGIS is another GIS tool that is being used by GIS developers to deal with Vector and Raster data types and it does almost the same tasks as ArcGIS Pro but learning it will certainly ease your work and is a privilege too.

ArcGIS Online

After learning the two mentioned tools, users can also learn that ArcGIS Online tools like Operational Dashboards and Story Maps are used for data Visualization and to extract insights from spatial data by connecting them with maps, graphs, charts, sounds, and videos.

After learning digitization and performing some analysis on spatial data, GIS users get themselves involved in storing, managing, and querying spatial data in databases. In order to deal with spatial data, there are a couple of Relational Database Management Systems which handle spatial data, and the most famous one is known as PostgreSQL. By installing the PostGIS extension to PostgreSQL, the tool will handle data having spatial information.

Once you got a complete understanding of the GIS tools and running spatial functions on PostGIS, then GIS users try to boost their skills in dealing with web GIS. It means they try to learn to code. The first step in this field is to start learning web programming like HTML, CSS, and JavaScript and they concentrate mainly on one JavaScript mapping library like leaflet, openlayers, or Mapbox. After learning vanilla JavaScript, GIS users try to learn at least one web framework like VueJS, Angular, AngularJS, or ReactJS. In this stage, GIS users try to learn how to create APIs and how to fetch the data coming from APIs into the fron-end and using how to deal with spatial API which is coming from third-party tools like Geoserver.

GIS developers in order to excel in their career, start learning and working with a couple of advanced analysis tools like Google Earth Engine and some data manipulation engines like FME or to make their GIS work automated. So, by learning these tools, GIS developer not only boosts their GIS skills, but they will get their salaries increased. Along with all these, they try to learn Spatial AI algorithms to do some very advanced sort of analysis and build high-level interactive maps or operational dashboards. For automation purposes, GIS developers either choose R programming language or Python. The ArcPy Python library is widely used for GIS automation purposes, especially in ArcGIS pro or ArcMap and for data integration purposes FME platform is well-known through this tool, users can connect and transform data between hundreds of systems.

Learning never ends. Therefore GIS developers keep on exploring new tools to ease and further automate their tasks and do research in various ways to find a way to contribute to knowledge.