When we taste something we put it in our mouths and chew. The taste may be sweet, salty, bitter, or sour. I really don't like the taste of oysters. In my opinion, it tastes bad, I prefer not to eat it, but someone else could think I'm crazy and think it's the best thing in the world!
This is the same when we say someone has "bad taste" (also known as "poor taste"). It means we don't agree with that person's choice of something. It "tastes bad" to you, you don't like it. We say it to describe our feelings and state our opinions (and sometimes to criticize someone!)
If you agree with your friend that Jim Carrey is the most handsome actor, then you could say, "you have good taste in men! "
This is the same as movies, music, fashion etc. I could think you have bad taste in music but anyone who likes the same music as you will disagree with me!
So good taste or bad taste are all matters of opinion. You might think someone has bad taste in music or men but not everyone likes the same kind of men! It is really up to the individual preference.
Do you know anyone who has good or bad taste in fashion? Can you write a sentence using "bad taste" or "good taste"?