Help a brother peel this layer of the onion off

If I throw BTC in a trust wallet and I get the key for it and delete Trust wallet, can I download another app, put those keys in and see my coins?

I normally give a couple ounces of silver to all my nieces and nephews and children, there’s 10 total, and every Christmas I tell him the same thing that ounce of silver will grow in value as their value in society grows.

None of them deal with crypto but they all have smart phones. I wanna start giving on BTC and tell them the same thing, that it will grow as they do.

I can make all of my own metal keys on a key ring to give each one of them. I’m not 100% sure if that’s the right way to go about it.

Any help would be appreciated.