no possible way for an accurate answer on this forum, not enough info. to get the info that pertains to your personal situation, make an appointment with your priest, lay out all the facts pertaining to your marital history, your prospective partner’s marital history, baptismal staus and so forth, It is a lot of info and no need to relate any of it here. The priest will help you detemine what steps should be taken.
short answer: the Catholic church considers marriages between two non-Catholics who were otherwise free to marry as valid until proven otherwise.
The canon law tribunal of the Catholic diocese where either party resides or where the marriage took place conducts the investigation. The only one who can apply for this is one of the parties to the marriage in question, and then only after it has irretrievably broken down (usually after civil divorce, which does not end a valid marriage).
it is useless and misleading to compare one marriage situation to another, as frequently occurs in discussions on these questions, because all the facts are never going to be the same, each situation is unique.
