The exact details depend upon what format you are using to save your Simulink output. It can be saved as a Simulink dataset, an array, structure with time etc. please see https://www.mathworks.com/help/simulink/ug/data-format-for-logged-simulation-data.html#bur96_r
Let's say you output your data as a SimulationOutput dataset, this is the default.
In this case after you run your simulation you should see a variable named out in your workspace.
To plot, for example, the output assigned to the second outport in the root level of your Simulink over the time range 0.25 to 0.5, you would use:
plot(out.yout{2}.Values.Time,out.yout{2}.Values.Data)
xlim([0.25,0.50])
You can also use the Simulation Data Inspector, which gives nice interactive tools for plotting logged signals, please see https://www.mathworks.com/help/simulink/slref/simulationdatainspector.html
