Download and install VScode for your system.
Use nodejs to setup npm. Use the LTS version.
Use a VScode plug-in to draw as code.
- Use a graph for procedures and data-flow
- Use a class diagram to model objects and what they can do
- Use a state diagram to depict the system as a set of states and transitions
- Use a sequence diagram to show an example sequence-flow
Try the live editor for an easy introduction.