To get the plot, you need to call the plot function without the = sign, like this:
plot(p, z, marker=:heg, leg=false, linewidth=2, linecolor=:black)
The error is because Julia thinks you are bounding a named tuple to the variable plot and this named tuple does not have values for p and z fields.
Also, it is useful for this forum to quote your code with backticks 
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Thanks a lot. this was too silly an error to make . Thank you anyways. also, i’ll keep the backticks in mind.
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Sure! We all make this kind of silly mistakes everyday 
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