With Wholesale module enable only.

Step 1: Create New Customer

• Go to Sales > Customers 

• Then click on "Create New" button.

Step 2: Select customer group

• Select the customer group of the customer, this will decide the price group of your customer

Step 3: Select Sales Rep (Optional)

• Select the sales rep for your customer

Step 4: Set Customer Payment term and Credit limit (Optional)

• Select your customer payment term and Credit limit

Step 5: Enter Customer billing and shipping address