You can add random friends using Friends menu. Every 8 hours the list of random friends is updated and you can send a request by selecting a friend you want to add tapping "Add" button. You can send requests to 4 people at a time and wait for the next 8 hours for the list to update or spend 5 diamonds to update it immediately. Please, note that you have to wait for these players to accept your request. Only after that you will be able to visit theirs Albions, send gifts and communicate.