This depends on the individual network and the bundle you have purchased.
Sim Local accepts Paypal, Visa and all cards associated with Visa (Visa PrePaid, Visa Premium Deferred Debit, etc), Mastercard and all cards associated with Mastercard (Maestro, etc.). All credit/debit card transactions on simlocal.com are processed securely by Judopay to keep your information safe.
You can request to have your existing number transferred to your eSIM by contacting your network provider.
Yes, as long as you have an eSIM enabled phone.