a)
1. Is arriving
2. I`ll have
3. I am meeting
4. Are not going to catch
5. Is finishing
(Present continuos to express the future)
b)
On the coming weekend I am going to go shopping with my mom to buy some new clothes and products. Also I am visiting my grandparents on the Sunday and having lunch with my best friend, then me and my friend are going to have a party at 10:00 p.m. with all of my classmates. Me and my brother/sister/I (один из вариантов: Я и мой брат/сестра/я) will go to the cinema to watch some fresh films and we/I will definitely buy popcorn!