Introduction by example
You need a data range and instructions how to handle the data. An example:
At https://www.cpb.nl/cijfer/actualisatie-middellangetermijnverkenning-2018-2021-verwerking-regeerakkoord a spreadsheet wit data can be downloaded. In 2017 we are interested how much money Dutch people will pay for medical insurance in the future. A CSV file is generated with name "CPB_Nominale_zorgpremie". It contains:
2006, 926 2007, 1001 2008, 1049 2009, 1059 2010, 1095 2011, 1199 2012, 1226 2013, 1213 2014, 1098 2015, 1158 2016, 1199 2017, 1290 2018, 1359 2019, 1431 2020, 1526 2021, 1601
From a terminal gnuplot is started:
wiebe@wswl:~$ gnuplot G N U P L O T Version 5.0 patchlevel 3 last modified 2016-02-21 Copyright (C) 1986-1993, 1998, 2004, 2007-2016 Thomas Williams, Colin Kelley and many others gnuplot home: http://www.gnuplot.info faq, bugs, etc: type "help FAQ" immediate help: type "help" (plot window: hit 'h') Terminal type set to 'qt' gnuplot> set size ratio 0.5 gnuplot> plot 'CPB_Nominale_zorgpremie' with linespoints gnuplot>
The range is plotted in a new window and from there you can export to SVG (first button top left).
If you're not happy with the results you can post edit in Inkscape. The result should be:
After you got the taste of it
Creating a plot is very easy as you can see. Searching the net is not as useful as expected, many people see gnuplot as some sort of "higher art". Possibilities are endless.
What to do for a basic understanding? RTM! Go here: http://www.gnuplot.info/documentation.html