I can’t download the free apps that I had on my previous iPhone
Do you use the same Apple ID?
and it won’t take a prepaid Visa card
Please read this carefully to understand what a prepaid Visa card is, and how to use it, what you can do with it, etc.
For App Store and iTunes Store you need to have a payment method on file, even if the app you want to download is free. You can use Apple gift card.
See also -> Payment methods you can use with your Apple ID
Payment methods you can use with your Apple ID – Apple Support (UK)
And if you still need help, get more help and assistant from Apple directly, see Contact Apple for support and service -> Contact Apple for support and service – Apple Support (UK)