First of all, you shouldn't feel horrible or apologize for never having been to a strike. There's a first time for everything, and this is yours. Be honest with your crew and the technical director/production manager.
What type of production are you working on: university, community, professional, etc? The type of production and the structure of the management will tend to dictate the stage manager's role in strike. For some productions, the stage manager has no role in strike other than to remove his/her personal belongings from the booth/backstage and to turn in the production book for archival purposes. In other strikes, stage management is responsible for striking props, furniture, and costumes to areas designated by the departments as well as pulling up safety tape, striking prop tables and running lights, etc. Speak with the technical director/production manager/faculty advisor before strike to define exactly what is expected of you at strike. And don't be afraid to ask questions.
Here's the link to another thread that discusses the stage manager's role in strike:
Pre-strike.