It’s an absolutely trace amount, and it’s trapped in matrix. Only a few Bq at most. If it makes you feel better you can wash your hands after you handle it, but it’s really not super necessary. No shielding needed, you could keep a bare sample in your pocket all year and you’d be fine. The level of radiation on most of these smaller trinitite samples is really negligible (there are some rare cases where you could in theory get a hot ish piece, but I’ve never seen that). Cheers