You need a marketplace level 5 to trade Gold.
Some payment methods have a verification period, during which you cannot trade your Gold. It may take up to 42 days (Direct Debit) or 60 days (Credit Card, Paypal) to verify a purchase.
You cannot trade free gold gained from daily logins, email validation or other features.
If you want your gold to be available for trading immediately, you can use a different payment method like Bank Transfer, Amazon Pay, Sofort, Paysafecard or Giropay, if these are available in your country.