Open Instagram and go to your profile
Tap the menu icon
Go to Settings and privacy
Tap Privacy
Check your account type
Switch to a private account if your account is public
Remove followers you do not want to see your following list
Block specific users if you want them to have no access
Limit who can see your activity using privacy settings
Hide your activity status if needed
Restrict accounts you want to limit without blocking
Keep in mind Instagram does not fully let you hide your following list from all followers on a private account
Use a separate account if you want more privacy