i never stop talking about some of these so i might as well banish them to a single post! you might know about a lot of them already, but feel free to look anyway

• Adobe Animate (Flash) → OpenToonz, Synfig Studio, or Pencil2D 
  
• Adobe Audition → Audacity
  
• Adobe Illustrator → Inkscape 
  
• Adobe Photoshop → GNU Image Manipulation Program or Paint.NET
  
• Adobe Premiere Pro/After Effects → Fusion, Shotcut, OpenShot, Natron, or Blender
  
• Autodesk Maya → Blender 
  
• Clip Studio Paint/Paint Tool SAI → Krita, FireAlpaca, (both also include animation tools!) or MediBang Paint
  
• FL Studio → LMMS
  
• Microsoft Office → LibreOffice or Calligra Suite 
  
• Scrivener → Celtx (sort of?) or Evernote
  
• VLC media player → VLC media player lol
  

freeware can be a great opportunity to get a feel for something and learn a new skill. and in some cases, the free versions are almost as powerful, so you might find that you saved a lot of money but made work that was just about equal to what you might have done with paid software!