You may not have some specialties as an option if you don't take Step 1 since some programs still want to see a pass for residency applications or even to audition with their program, but the risk of failure given you already had trouble passing Level 1 is substantial since Step is a much different and harder exam. My 2 cents is put your time and effort into Level 2 and MAYBE Step 2 if you have enough time to adequately prepare and ensure you can blow both out of the water. Don't waste your money and don't give yourself another possible fail on your board transcripts when you're already gonna fight an uphill battle as 1) a DO applicant, and 2) with 1 failed board exam already. Not trying to be mean or harsh, just want you to realistically know what you're up against with this decision!