To configure and manage your store’s Shipping Methods, you would have previously gone to Settings ->Shipping ->Shipping Methods in the old Admin.
With the new admin, you’ll go to Settings ->Shipping.
Once there, click on the “Select Methods” button underneath “Shipping Methods” to manage your store’s Shipping Methods.
The same basic functionality as before is still present. However, you now have an additional advantage in that you can create multiple methods for each carrier in one shot!