Do not commit to marriage until you have shared everything that needs to be shared. And you know that they understand and accept it.
An important goal of shiduch dating is to know that you both know that you are getting into a viable relationship. That you both know what you are signing up for and accept the less desirable with the wonderful.
Know what you will have to share. Especially the aspects about you and your life that some people are not ready to accept (this might be medical conditions, family situations, deal-breakers, location restrictions).
Share everything that needs to be shared. And confirm that you know that they accept it all – with all the nuances. Ask them to tell you what they understand about whatever it is. “I am not sure I shared that clearly. Can you please tell me what you understood and I can fill in.”