The future continuous is formed with 'will/won't + be + -ing' I will be meeting David tomorrow.
We use the future continuous to talk about a temporary action in progress at a particular time in the future. They'll be celebrating their tenth anniversary next weekend. I won't be working on Monday.
We can also use the future continuous to ask questions about people's plans, especially if we want them to do something. Will you be coming to the party? (I want you to come) Will you be using the car this evening? (I want to use it)
We can also use this form to give reasons for not being able to do something. I'm afraid I can't come to the party. I'll be working late.
We use 'going to' to talk about intentions – (the things we plan to do) I'm going to buy a new car at the end of the year. (I want to do this but I haven't ordered the car)
We use the present continuous for fixed arrangements – (things we have already planned or organised) I'm getting a new car in two days time. - (The car has been ordered)
We normally use a time reference with the present continuous unless the listener knows the context. I'm starting an art course next week.