Each Who Wants To Be A Millionaire game start with the Fastest Finger First round.
After that, you will need to answer 12 or 15 questions correct in order to win a million (UK + FR version have 12, others have 15). There are 2 save havens somewhere during these 15 questions (highlighted in white) . If you've passed this haven and got a question wrong after that, you'll win the amount of cash displayed at the safe haven.
As for all 4 other WWTBAM versions, you can hold the back button on your phone and translate the question if needed and besides, look up the answer. Once all 4 answers have appeared, hold the back button on your phone. The question and answers should still be visible. Once you've figured out using google/the internet what the answer is, go back to the game and immediately press the correct answer. (to make sure that you get the achievements for finishing the game in 60 and in 90 seconds) Don't use any lifelines during your first run, and you should amount a whopping 13 achievements (14 if you've did the fastest finger achievement correct).
Some achievements only unlock after going to the achievements tab and then backing out to the main menu.