If you are asking if Hebrew Catholics must follow Jewish law, and in doing so to celebrate Jewish holidays, as a condition of salvation, then no. St. Paul said:
Therefore let no one pass judgment on you in questions of food and drink or with regard to a festival or a new moon or a sabbath. These are only a shadow of what is to come; but the substance belongs to Christ (Col. 2:16-17).
Many Catholics who have entered the Church from Judaism choose to celebrate Jewish holidays and to retain other aspects of Judaism, but they do so to maintain their heritage as Jews, not because they are bound to do so as Christians.
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