1. 'I played' is a neutral statement. For example: A: What did you do yesterday afternoon? B: I played golf. 2. 'I did play' is only used when you want to add special emphasis, especially if you want to make a contrast or contradict someone. For example: 'I hated sport when I was at school. I couldn't swim and I was terrible at football and rugby. But I did play tennis sometimes. ' You say 'I did play tennis' here to emphasise the contrast. or A: Why didn't you play in the football match yesterday? B: I did play yesterday. A: Really? I didn't see you there. Speaker B says 'I did play yesterday' to contradict what Speaker A has said. I hope that's clear for you!

When you say "I played" you're saying that the action is finished. If you say "I did play" you are adding emphasis, in other words you're saying something like "I did play(please believe me)"

There are three situations you would say "did + verb" instead of "verb + ed": 1) In questions 2) In negative sentences 3) For special emphasis "I did play" can only be number 3 because if it were a negative sentence, "not" would be between "did" and "play". If it were a question, the verb would be placed before the subject. Thus it can only be number three. The only difference between "I played" and "I did play" is emphasis, as has been explained by Su Ki and Rafael.

By the way, "¿" doesn't exist in English. You only need one question mark.