Anki can be configured to show cards in both a forward and reverse direction. If you want cards to only show from front->back, you can delete the reverse card.
If you have added cards to the "Basic (and [optional] reversed)" card type, you can change the cards to the "Basic" card type by selecting them in the Browse screen, then using the Change Note Type menu item. Select your Basic note type, choosing to keep Card 1, and discard Card 2.
If you have modified the Basic card template to add an unwanted reverse direction, you can modify it back instead:
- Edit a card
- Click the 'Cards' button
- You will see one or more tabs at the top representing each card type that will be created. Locate the card type you don't want, click the Options button, and remove the unwanted card template.