Heart rate zone don’t show

Hello,

I just did my first training yesterday and my heart went up to 163. Î’m a man and 54. Today I did a training through Garmin coach 10k. This time my heart rate went up to 190. First I would like to know why the vivoactive 5 didn’t show me any heart rate zone. It didn’t advise me to stick to one of these zones. Should n’t it give me some guidelines? And second I don’t understand why my maximum heart beat is still 163. it’s a huge difference. I thought the watch was analysing our data and adjusting in consequence Thank you if you can help