If I file bankruptcy, will get married and petitioned by my husband to be, will it affect my petition to him?

No, based on the info here.

Understand it is very hard to answer a question for someone who provides no background information or details. I am going to assume you are talking about an immigration petition. Bankruptcy lawyers do not generally know much about immigration cases. Although it has been more than 20 years since immigration was part of my practice of law, as long as you are able to show that you can support your husband and provide him with medical insurance to keep him from becoming a public charge, you having filed bankruptcy should not affect an otherwise good affidavit of support.

Your question is not very clear. Are you asking if your filing BR will affect your husband-to-be? Or are you concerned that his filing for BR may affect you? You may want to re-phrase your question. But let me tell you in general that spouses are not liable for debts the other spouse incurred before the marriage.