Temat: Potrzebuje kogoś dobrego z angielskiego

Dear Pat
I've got to tell you about someone I've met recently.

Her name is Isabelle, I've met her at the party three days ago, "a party", gość z którym rozmawiasz nie ma pojęcia o jakim przyjęciu mówisz dlatego używasz indefinite article
First of all, we had been standing next to ourselfs in a queque Zmieniłbym "first of all" na coś innego, przykładowo "at first", "we were standing next to each other in a queue", had been używasz w sytuacji gdy zaraz po tym występuje kolejna czynność w -ing.
and we ordered the same drinks - beer with lemonade,
And later we have discovered that we have common friend - Mark. dodałbym - "after a short conversation we discovered that we have a common friend - Mark"
Friendship with mark isn't the only thing we have in common,
She's also keen on playing tennis, and guess what, she also loves films with Robert de Niro!
As Me and You!
What a suprise! I'm seeing her next saturday, we are going to watch a new
movie with our favorite actor in a theater near me.
She's such a wonderful person, Isa is tall, very beautiful, and she has brown hair.
I'm sure you will like her! During holidays, when you come We can go "when you come" dodaj po tym gdzie, samo come nic nie znaczy. We, you niekoniecznie z dużej litery, piszesz do kumpla nie do prezydenta
to the lakes of Mazury with my uncle, he has his own boat! "we can visit the Masurian lake district with my uncle, he owns a boat."
What a great time we are going to have!

Looking forward to hearing from you soon!
Best, 
XYZ