Important papers?

🌸Karaline🐝 • Breathe deeply, tomorrow isn`t yesterday
My MIL is a bit of a control freak. My husband is signing up for the Air Force (just turned in all the paperwork). I told my husband I want a fireproof lock box for all our important papers (birth certificates, SS cards, marriage certificate) before he leaves for basic. He told me his mom wants to hold on to his papers until we get our own place.
Will I need his birth certificate or SS card for anything while he's in basic or technical training? (I'm 14wks pregnant so I'll be using Tricare right away)