I have two large datasets, call them “seq” and “rbspsd”. I can plot each alone using ListPlot (i.e., ListPlot[seq] and ListPlot[rbspsd]), but not together, i.e.
(note if your data is very different the dots may not be all shown unless you limit your plot region to an area where both can be visible within the displayable graphics plot result)
so in summary the structure of your data not in the form {{1,2,3},{4,5,6}}
you might try this and see if the data structure is ok:
ListPlot[{data//Flatten,data2//Flatten}]
if not, then you have {x,y} data or something else. ListPlot handles x,y but again the structure of the list needs to be one of the ones ListPlot is ready to accept. restructure your List[].
you may not get some of the prime online content (ready to plot star data, ready to plot geological data), and you cannot use it for work-(job) related uses of any kind (not even so called non-profit gov use). but if you have such need you can upgrade your license at a discount having already bought a lower license - if you do it say in a year or a few.
one could use Flatten, or Part[], ie b:=a[[1,all,“sam”]], or looping (for i=1…10 do a[[i]]:=b[[j]). but you’ll definitely want to restructure List[]s using ReplaceAll not “code programming loops”. it will be as or more efficient as well. once in a while you might replace the Head[] of list with Sequence.
here are two colors (obviously the list plot flow may not be as intended. you realize ListPlot flows to the right at each datapoint i assume unless x,y is given)