Basically, Magento doesn’t provide functionality to enable total summary in shipping step. So we have to change some of the files.
Let’s follow below steps:

Step 1: To enable summary, you need to override below file.

app/code/Magento/Checkout/view/frontend/web/js/view/summary/abstract-total.js

Override isFullMode() function

isFullMode: function() {
            if (!this.getTotals()) {
                return false;
            }
           // return stepNavigator.isProcessed('shipping');
            return true;
        }

 

Step:2 To change shipping price value on selection of the shipping method. You can override the following file.

app/code/Magento/Checkout/view/frontend/web/js/view/summary/shipping.js

Change getValue() function.

getValue: function() {

                if (!this.isCalculated()) {
                    return this.notCalculatedMessage;
                }
                //var price =  this.totals().shipping_amount; /* comment this line and add below two lines. */
                 var shippingMethod = quote.shippingMethod();
                var price =  shippingMethod.amount;
                return this.getFormattedPrice(price);
            }