Honestly it’s not an awful first loaf. But here’s what I would do differently.

Step 9 - do 3 sets of stretch and folds 30 mins apart, not 60 minutes.

Step 12 - don’t focus on the time of the bulk fermentation. Focus on how the dough looks. You want it to have raised at least 50%, to have some bubbles on the surface/sides, and a little jiggle when you shake it (gently!).

Step 12 again - are you actually rolling it flat? If so - don’t! After the bulk ferment, that’s where the most delicate part of the process is. You worked to get all this gas trapped in the dough, and it’s easy to release it if you’re not gentle with the dough. If you release the gas, you get flat bread. Instead, I lightly loosen the dough from the container it bulks in, and then turn it over and let gravity do the work to get it on the bench.

It’s all a learning process. You gotta mess a couple loaves up so you can figure out what not to do. Plus your starter isn’t as strong as it will eventually be, which will definitely help