The future simple verb tense "going to" is used in the following situations:

Planned Events - When a future event that has been planned before the time of speaking.

• I am going to Mexico in a few days.
• We are not going to work next week.
• They are going to university next year.

Predictions - To make a future prediction based on facts.

• There is going to be a really big storm in a few hours.
• The test next week is going to be really hard.
• The puppies are cute. I am sure someone is going to adapt them.

Intentions - To state the something that is intended to take place in the future, in informal conversations.

• I am going to be a rich person someday.
• We are going to pass the test.
• The puppies are going to make a big mess in house.