bampilot06 - continued from Strava:
Yeah, you're not a plebe anymore - train by power, not HR
On your Garmin, or Garmin Connect, input your FTP and let it calculate the zones for you. Until you're feeling fit enough to really give it a good go with some hard efforts, I'd just pop in something in the region of your estimated FTP, erring on the conservative side.
If you really want to, you can track down some widgets and screens on Connect IQ for your 530 for nice visual representation while you're riding.