Opened attachment from Samsung Android

I was waiting on a legitimate transaction receipt of me paying my doctor's office bill online. The billing dept told me on the phone the receipt would be sent to my main personal email within half hour.

Coincidentally, I got an email with an invoice so I just opened it immediately to check on it and realized it was for something else and one of those usual scam invoice emails that I normally mark as spam. If I wasn't already expecting a receipt during that EXACT time, I wouldn't have downloaded the attachment.

I've already deleted the file immediately from my phone and Adobe Acrobat. I also marked the email as spam and deleted it. But what else do I need to do? What vulnerabilities have I exposed myself to? This is my main, primary email.