Here's how to make the positive:

• I will meet him later (I'll ..)
• You will come (you'll..)
• It will rain tomorrow (it'll)
• She will be late (she'll..)
• He will help us later (he'll..)
• We will get married in September (we'll)
• They will cook dinner (they'll..)

To make the negative, just add 'not':

• I will not go (I won't ..)
• You will not be late (you won't ..)
• It will not snow tomorrow (it won't..)
• She will not get the job (she won't..)
• He will not pass the exam (he won't ..)
• We will not come (we won't..)
• They will not stop (they won't ..)

Here are the past simple 'yes / no' questions :

• Will I go?
• Will you come early?
• Will it be cold?
• Will she dance?
• Will he arrive soon?
• Will we cook?
• Will they leave?

To make 'wh' questions with 'be' (the question word just goes at the beginning, everything else is the same):

• Where will I go?
• Why will you come early?
• When will it be cold?
• Who will she dance with?
• What time will he arrive soon?
• What will we cook?
• When will they leave?

Usage:

1. To express predictions about future.
   • There will be next-generation robots in 2050.
2. Promises / requests / refusals / offers / decisions at the moment of speaking.
   • I'll help you with your homework.
   • I Will you give me a hand?
   • I won't go!
3. To express actions that are not in our control.
   • It will be Sunday tomorrow.