There are four different design's that are mentioned in the tutorial,and there are some errors as well that have to be fixed in this tutorial
coming to your question.convergence is The criteria of HFSS is based on S-parameter at the ports. S-parameter is the integration of field intensity on the port surface. So, S-parameter is considered convergent by the criteria we set up. Like a minimum of 0.02 0r 0.01.
you specify the number of passes,these are all user dependent values.how to determine the number of passes would say just go with the default,if they converge good enough if not enter a higher number of passes
Hope that helps
Regards