Well, gosh, you certainly start with a DRE!
If anything feels suspicious to a doctor/urologist, the normal sequence would be to then do an MRI scan, followed by a rectal or perineal biopsy guided by what the MRI shows, if it indeed does show something.
If that is the sequence followed, please don't be too nervous or scared of the biopsy; it's typically not a big deal, and not particularly painful.