I am not sure exactly what takes time in your example but you should know that Julia functions get optimized and compiled the first time they are run. Therefore, if you use a large number of packages that make calls to a large number of functions, then the first time the commands are executed in the Julia session there will be some overhead.
The recommended workflow is therefore rarely to use julia script.jl but to start a julia session and run e.g. include("script.jl"). The first time, things are compiled, the second time will be fast.
1 min+ for first plot is, of course, a very long time and it would be interesting to analyze if there is something special that takes up the majority of that time.