To confirm, are you asking about the Mathworks toolbox System Composer that was introduced in R2019a ? If so then https://www.mathworks.com/help/systemcomposer/getting-started-with-system-composer.html has some tutorial links for it.
Or are you asking about the tool that used to be known as Xilinx System Composer, but is now known as Vitis Model Composer https://www.xilinx.com/video/hardware/model-composer-product-overview.html (Xilinx is now owned by AMD)
Or are you asking about the tool that used to be known as Vivado System Generator, which was also offered by Xilinx ? https://www.xilinx.com/support/documentation-navigation/design-hubs/2020-1/dh0014-vivado-system-generator-hub.html ?
