Any ideas on fixing my credit?

• credit card balance transfer
• applying for credit card
• apply for a credit card
• check credit score
• longer term care

I need to increase my credit score to qualify for a mortgage. I have some medical bills that are about $2000 that are in collections. Should I pay those collections off? I asked the collection agency for a pay-for-delete, but they refused. I just recently purchased a new car, had to have a reliable car because I work two jobs. Will that bring my score down? I have two 30 day late payments, one on a credit card, one on an installment loan-which is now paid in full. I sent goodwill letters to those companies asking for deletion, but they refused. I filed bankruptcy 5 years ago. How bad is that impacting my score at this time? Any advice? Be nice, you don't know my situation. Thanks

Any ideas on fixing my credit?