3rd loaf (but first that was edible)

Hello! First off wanted to say thanks for all the resources and info here. It's because of people on here being generous with their knowledge that newbies like me can even make something edible.

As title suggests, I failed twice but on my third loaf I think I've done ok!

My starter is quite young (14 days or so) but managed to get her active with heavy overnight feedings.

Ingredients:
100g of active starter
400g white bread flour (13.8% protein)
100g wholemeal flour
350g water
10g sea salt

I feed the starter in the morning (25g starter 50g flour (5g wholemeal 45g white bread flour & 45g water.

Wait 3 hours then bring my flour and 90% of the total water together.

After one hour I mix 100g of the starter with the remaining water (30g) and incorporate into my dough.

Add 10g sea salt and leave for 45 mins.

4 x stretch and folds with 30 mins in between.

Pre shape, wait another 30 mins.

Shape and transfer to rice flour/towel lined mixing bowl (don't have a basket yet!)

Into the fridge overnight for 9 hours.

First thing in the morning preheat oven and casserole dish (it's all I have!) to 240C for 30 mins.

Take dough out, score in a cross cos I'm not ready to get fancy yet.

20 mins at 240c with lid on, reduce temp to 200c for another 20 mins with lid off.

Thermometer said 98/99C in centre so I transferred to rack.

And this was the result! Any tips on my method? I'm totally open to any feedback you may have. Be brutal. I have so much to learn!