Excellent English, just a few suggestions:

Chistmas time

It's Christmas time. In all the city we can see a lot of lights and color! In the main square of the city a very big Christmas tree is being put up (or some other past participle -- but not "made")!
But I have only one (use one for emphasis) problem... the presents! I don't know what to give (to) my boyfriend and (to) my parents! I need help, can someone suggest me something for me to give?

"In all the city" is correct, but there are several more typical ways to say that: "In the whole city," "in the entire city," "Everywhere in the city."

Sorry, I have no idea what presents you should buy ;)