1. I run Julia on my smartphone and often use it as calculator.
2. You typically only need Plots.jl for most needs. See https://docs.juliaplots.org/stable/
3. See https://juliaacademy.com
Another alternative environment are Pluto notebooks. It's reactive like a spreadsheet, but easy to use in your browser.
I have several users without much coding experience using Pluto notebooks just to generate plots from CSV files. They are finding the combination of a web based interface, reactive UI, and fast execution easier to use than a MATLAB Live script.