Mme Sra is either not available or she is working on your text.

You write very well, despite a few grammatical and syntax errors many of which you could probably avoid.

To get you started, I enclose a few to help you with self corrections. Do look for other similar ones, in addition to syntax errors, which I will leave to Mme Sra, who does a much better job than I can.

Some of the things to watch out:
agreement in number between subject and verb, and between nouns and adjectives.

Also watch out the use between qui and que. The former acts as a subject (je, tu,...), and the latter as an object (me, te,...).

Usually if you write a long text, leave it aside for a day, and reread it, you will most likely find some corrections/mistakes.

Félicitations et bon travail!

Here are some of the corrections you could do:
Nous avons (décorér) nos Noël
Mes frères et soeur (faites)
ils (créés)
sont très brillant( ) et élégant( )
(garland) brillant( ) => guirlande (n.f.)
l'étoile (big) que nous (vient) d'acheter
(sur notre arbre de Noël) should follow ..."de placer"
Les ornements qu(i) j'aime : que
sont musicale( )
Je souhai(t)