When you first SSH into a SLURM cluster, you’ll be presented with a shell on the login server. Never do any heavy processing on the login server, it should only be used for light activity like basic shell usage (copying, etc.).
To get access to another node, first you need to allocate resources.
One quick way to get an interactive session is to run the command
srun -p example_partition1,example_partition2 -t 01:00:00 --pty bash -i