Because the Canary Islands are part of Spain the currency on the islands is Euro. On all the islands of the Canary Island money withdraw is not a problem. All over the island, especially in touristic areas, you will find ATMs.
On the Canary Islands it is possible to pay with credit cards at most of the larger hotels and restaurants in the touristic locations. But always make sure you have more than enough cash or a banking card with you in case it isn’t possible to pay with credit card.