Ballet wallet question

I recently acquired a few crypto cards that get uploaded to ballet wallet. Is the card a secure form to just hold it there and not upload it to ballet? Or if I just have it in ballet is this safe like a cold wallet? Basiclly im new to this so I transfered about half my btc to coinbase because I needed the funds, yet to sell them tho. And will still have about 0.02 btc left. 0.01 in coinbase and another 0.013 in the card form shortly. Aside from that I'll take any advice or point me to a place to read up on my questions.