How can I retrieve my photos from the phone?

You've checked your https://photos.google.com/ page, right? Just wanted to be sure.

How did you determine that the charging port and display were the parts that are damaged? I'm guessing you took it to a repair shop and that's what they told you, is that right? Does the phone have any signs of life, like vibrating or making sounds?

Anyway, the charging port and screen are very much replaceable, so if it's that important to you. it is something you can save a lot of money on by doing it yourself. iFixit has step by step instructions, and if you follow them most anyone can manage their own repairs.

The charging port can be found on places like eBay, Amazon, AliExpress and others fairly cheaply. Here's one example for under $10 USD, including shipping.

Original Type C USB Charger Charging Port Dock Connector Flex Cable For Google Pixel 4a replacement

And a guide to show you how.

Google Pixel 4a Charging Port Replacement - iFixit Repair Guide

For the screen, you can get a functional one (with screen burn in, apparently) for about $50 USD from AliExpress; new ones are quite a bit more expensive, but if all you need is to get the photos off, this should do the job. I realize it's still not cheap, but keep an eye out on websites and shop around for a price you can afford. There are often screens being sold on places like eBay that are cracked but still functional that can be gotten fairly inexpensively.

Google Pixel 4a Lcd Display Touch Screen Digitizer Assembly Replacement For Google Pixel 4a Lcd With Burn Shadows - Mobile Phone Lcd Screens - AliExpress

There is, of course, a guide for the screen, but if you decide to replace the charging port, you'll have to take the screen off anyway. Regardless, here the guide you would need for just the screen.

Google Pixel 4a Screen Replacement - iFixit Repair Guide

In the case of water damage, it's always a good idea to replace the battery, so be prepared that it may still not work even after replacing the screen and charging port, because it may need a battery as well.