At a recent rally, President Trump said, "Even with the 'Me Too' movement, we can't say this, but I'll say it anyway: You're better looking." That might have left several of you even more confused about sexual harassment than before.
Can still tell someone they're attractive?
Yes. You still have a right to free speech. However, as with everything you do, there might be consequences. At work, someone's attractiveness usually isn't work-related, so it is probably best to keep your opinions to yourself about it. Conversely, if you are on a date with someone you find attractive, they might want to know your opinion.
We might be making this a lot harder than it is. Just as you learned it isn't wise to tell your parents you think they are stupid, your spouse they are fat, etc., you can learn not to make your personal interests in someone more important than their interests in going to work, walking down the street, etc. without disruption.
People typically get into trouble around sexual harassment because they have thought only of themselves and forgotten that others have just as much right to what they want.
Sexual harassment is more often about control than about sex.