The first sustainable goal is to end poverty, which is defined as living on less than US$ 1.90 a day, the conditions by which still almost 800 million people are affected (this is nearly 2.5 times more than the entire population of the United States!). This totals to 11% of the whole globe being undernourished, without access to education, proper living conditions, and especially vulnerable to climate change.
While you can’t stop the poverty yourself, you should understand that the things you take for granted daily are not even in the most dare dreams of so many people! You should also realize that what is indeed a small amount for you (such as dinner for two at an average place) is the same as some people have as their monthly budget.
Most of the people affected by severe poverty live in Southern Asia and sub-Saharan Africa. It makes sense, therefore, to look for the organizations that specialize in helping these regions. There are many ways in which you can get involved and help those in need. Donating money is not always attainable, but neither it is the best solution.