Is it okay to give up something like chocolate or soft-drink for Lent? These are acceptable sacrifices, but we should strive to give up something that fits our age and circumstances. A teenager may give up soft-drink, and that's a decent sacrifice. But what if they give up social media? That might be a better sacrifice.
For an adult, merely giving up chocolate might be going too easy on ourselves. Only you can judge your sacrifice, but sacrifices should cost you. In other words, your sacrifice should be substantial so that you feel it. It should have an impact on your day, week, or season. Passing on doughnuts at morning tea doesn't have a tremendous impact on your day. Giving your lunch money to someone in need or to a good cause, however, definitely costs you, because you end up hungry for lunch! That sounds like a terrible proposition, but this is precisely what transforms people.
This is what makes the difference between an ordinary soul and a saint. Remember, sainthood is our goal! Keep that in mind when choosing your sacrifice. And if you've already declared merely chocolate to be your sacrifice, well, keep in mind we live in a world where we are free to change our minds. You can change your mind and do something different, and you don't have to answer to anyone but yourself and God.