LA = Local Anesthetic.
LATP has replaced TRUS biopsies, and has at least a 30x lower infection risk, and can access the whole prostate (which TRUS can't). Many places which have switched to LATP have had no infection cases at all, so I think you don't need to worry about infection risk. It has also replaced some transperineal template biopsies (although it's not a template biopsy).
A biopsy is the only way to diagnose prostate cancer (unless it's spread so widely it's unmistakable in MRI or bone scans). If cancer is found, the biopsy will give the Gleason score (or Gleason Grade) which is a measure of the aggressiveness of the cancer, and also where it's located in the prostate, so it's the key diagnosis procedure.
It typically takes about 3 weeks to get the results, and that's usually an anxious time.
You may also be asked to have a nuclear bone scan to check for any spread. This doesn't mean they suspect any spread, it's routine in many hospitals.
The biopsy will cause blood in semen and urine. The semen in particular can look just like tomato ketchup - that's normal, don't worry. However, it's very alarming if you haven't been warned to expect it beforehand. Blood in urine is usually very minor.