PRESENT CONTINUOUS FOR FUTURE + BE GOING TO

We often use the present continuous tense to talk about the future. Of course, we normally use the present continuous to talk about action happening in the present, but if we add a future word, we can use it to talk about the future. (By "future word" we mean words or expressions like tomorrow, next week, in June. The future word may be clearly expressed or understood from the context.)
Sometimes there is no real difference between an intention (going to) and a plan (present continuous). In this case, it doesn't matter which we use.

For good practice go to these websites:
To be going to practice
Present Continuous for future practice
Just for fun:
British council teens