No, you don’t always need a pact to achieve your needs. All you need is the belief, will and intent to make it happen, perform a ritual, call on a spirit, candle spell or petition spell, and you can achieve almost anything you want.
Whatever it is you want, since you previously mentioned you wanted to work with a demon, identify the spirit (doesn’t always have to be a demon) that specializes in a particular area in which you need assistance, and call on them.
If you insist on doing a pact, advice was given in your other thread on how to do one, and you can also search the forum for that as well. Again though, you do NOT always need a pact in order to get what you need.