Hi Sarah, returning the favour :) The text is interesting and complicated - congratulations! There are a few mistakes though.

* In China, the two ceremonies are quite socialistic, = socialist describes political idea. Social is anything related to society. Which one did you mean in this context?
* The first month after the baby's birthday. Birthday is the day of birth every year. In this context it is better to say: One month after the baby is born.
the family often invites their parents and friends to celebrate the baby's birthday together.
* The samilar (A similar) celebration will be one year after his/her birth.

You can say "A similar celebration will be one year later" but in this particular context that would mean: one year after the celebration (since this sentence immediately follows your description of One-Month-Old Feast), which I guess is not what you meant.
The word "latter" has a different meaning: the second of the two (dernier en français). E.g. - Do you prefer chicken or duck? - The latter (i.e. I prefer duck)

* while the baby will chose is choosing what he wants (among the gifts?), nor neither his parents nor others shouldn't give (him) any induct or imply (hint or suggestion). The most important thing is the order of choose his choice (or in which he chooses). That could be regarded as a sign of his interesting, major (not sure what you meant) and even future.

Good luck! Keep up with the great job!