Coinbase is not linked to your bank account (it was just verification) and you need to deposit again.
What? Of course Coinbase links to your bank account! How do you think you can transfer funds to buy Bitcoin? You need to link your bank account or a credit card.
Do I need to transfer funds to Coinbase again (sepa)into euro to buy btc
Yes, you need to transfer funds in to buy Bitcoin. You can't buy Bitcoin with just $2 any longer, the fees will be greater than $2 for the transaction. If you click "Buy" it should give you the option to choose which bank account or credit card you want to use to fund that transaction. If you've not linked a bank account or credit card you will need to do so.
PM or post if you have other questions, I'd be happy to help you out.