On a high level, there are two types of software applications that you need as a beginner.
- 3D modeling Application
- Slicer Application
We need a 3D modeling application that helps you create a model. There are many applications which are free as well as paid. In the free tier, the best option that I found is tinkercad. It is very beginner-friendly and also a helpful community to support you. Once you master 3D modeling, the next stop would be Autodesk Fusion 360, which is free for hobbyists.
In the Slicer department, what worked best for me is Ultimaker Cura. It is free and there is a great community build around it for support. There are other options too such as PrusaSlicer, Simplify3D and Slic3er. However, I have not used it so far.