How do i get my tricare started?

My husband was a in the army reserves then he got picked for deployment and now he is Active duty. i was just moved to louisville KY because i was told i had to be near fort knox... I have no ideal how to get my tricare started? Theinsurancee i did have is gone now because he is deployed and was told i have tricare now... I have no ideal what i have to do or where i go to get it done. I know i have to go on bace but where do i go?