You can also prevent Instagram from connecting to your contacts. This will show you the accounts of people whose number you have in your phone.
Go to Account Center via the hamburger menu in your profile
Click on 'Your data and consents' and then on 'Upload contacts'
Turn off the slider next to 'Connect to Contacts'
Blocking people
If you don't want to set your account to private, but still want to make sure that certain people can't see your posts and stories, you can choose to block users. To do this, go to their profile, click on the three dots at the top right and click on 'Block'.
They can now no longer see anything on your profile. But keep in mind that a new (fake) account is job function email database quickly created, and someone can easily bypass the block in this way. They also do not receive a notification when you block them, but when they view your profile they can see that there are no posts. This allows them to deduce that they have been blocked. This is what it looks like to them:Example of what your Instagram profile looks like to a blocked follower