For simple data visualization tasks, remember you can often use the built-in tools available in programs such as Microsoft Word or Powerpoint, or Excel (or Google's Writer, Present or Sheets) to generate graphs and charts from data.
Online design tools such as Canva and Piktochart include some simple but versatile data visualization tools. Their advantage is that they include many flexible templates that help you incorporate your visualization in a professional-looking online or print-ready format.