Can 2-3 drop of pineapple juice on the left side of Apple Watch series 3 do something bad to watch?

Did you immediately wipe the juice drops off? If you did, it's not likely going to cause an issue.

You're welcome.

i need help to get my apple watch 3 series activation code can someone help me please?

You need to post your own question (threadjacking is rude) and provide as much information about your situation as possible.