Hello @Jose_Manuel_Alvarez and welcome to the ImageJ forum!
The easiest way is to install Fiji, which comes with the Trainable Weka Segmentation plugin and all its dependences already installed and ready to use.
No special card is needed because it runs in CPU. The CPU and amount of RAM depends on the size of the images you need to segment. The plugin is multi-threaded, so the more cores your CPU has, the fastest the plugin will execute.