A great weekend

Hi,

My name is Sandrine. I live in Paris but I come am from Nantes.

I'm very happy because this weekend I am going to visit my parent in Nantes. I am going to take the train tonight at 8 pm to go there. Tomorrow, my mother and me I will do go shopping and we will also have lunch with my cousine.
Tomorrow night, I am going to join my friends for a birthday's party. I'll have to cook a cake for it.

On Sunday, my mother and me I will go to the sea, in La Baule, if the weather is good. We will eat a big plate of seafoods and an icecream if our favorite restaurant is open.

Monday is a national day off in France. I am going to visit my dad. If the weather is good, we will do ride bicycles and we will also play tennis.

I also wish you a very good weekend !! This is ok, but more correct would be: I also hope you have a very good weekend!!

Very good! When using multiple sentences to describe something, you need to point back to the original subject in each sentence.

to go there = Nantes

for it = birthday party

A great weekend

Hi,

My name is Sandrine. I live in Paris but I come from Nantes.

I'm very happy because this weekend I am going to visit my parents in Nantes. I am going to take the train tonight at 8 pm. Tomorrow, my mother and me I will go shopping and we will lunch with my cousin. "Cousin" is the same, masculine or feminine.
Tomorrow night, I am going to join my friends for a birthday's party. I'll have to bake a cake. Cake, pies and breads are always "baked" not "cooked".

On Sunday, my mother and me will go to the seaside, in La Baule, if the weather is good. You could also say "coast" instead of "seaside". We will eat a big plate of seafoods and an icecream if our favorite restaurant is open.

Monday is a national day off in France. I going to visit my dad. If the weather is good, we will do bicycle go cycling and we will play tennis. You can chain verbs after "will", like "We will eat, drink, laugh and sleep."

I also wish you a very good weekend !!

A Great Weekend

Hi,

My name is Sandrine. I live in Paris but (I) come from Nantes.

I'm very happy because this weekend I am going to visit my parents in Nantes. I am going to take/catch the train (tonight) at 8 pm. Tomorrow, my mother and I (me) will do some shopping and (we) will lunch with my cousin. (cousine.) 
Tomorrow night, I am going to join my friends for a birthday (birthday's) party. I'll have to bake (cook) a cake.

On Sunday, my mother and I (me) will go to the seaside, in La Baule, if the weather is good. We will then eat a big plate of seafood(s) and (an) icecream if our favourite (favorit) restaurant is open.

Monday is a national holiday (day off) in France. I am going to visit my dad. If the weather is good, we will ride (do) bicycles and (we will) play tennis.

I also wish you a very good weekend !!

Sounds a very well-planned break. Hope it is enjoyable. In your second sentence you could also say 'I am going back to Nantes to visit my parents.'

A great weekend

Hi,

My name is Sandrine. I live in Paris but I come from Nantes.

I'm very happy because this weekend I'm going to visit my parents in Nantes. I going to take the train tonight at 8 pm. Tomorrow, my mother and me I will do shopping and we will lunch with my cousine.
Tomorrow night, I am going to join my friends for a birthday's party. I'll have to cook bake a cake.

On sunday, my mother and me I will go to the sea, in La Baule, if the weather is good. We will eat a big plate of seafoods and an icecream if our favorite restaurant is open.

Monday is a national day off in France. I am going to visit my dad. If the weather is good, we will do ride bicycles and we will play tennis.

I also wish you a very good weekend !!

C'est bien!!