When to take baby to the dentist?

My baby is 18 months and he has all teeth in the front and 4 back teeth.

The doctor suggested I take him so they clean up his teeth just so when he goes the second time he won’t be scared if that makes any sense.

I asked my mom what she thought and she’s a negative person most of the time so she said no it’s a bad idea they will hurt him.

I feel like I should listen to a doctor and other moms who have children around the same age as mine instead.

So I want to know when should I take my son to the dentist if now or in a few months???