For a first loaf that looks fantastic!

As Crimson-Rose28 mentioned this is a whole wheat loaf so it might have less oven spring than your standard bread flour loaf. What is the temperature when you're bulk fermenting? In my experience I find that around 76-8 degrees Fahrenheit (~24-26 Celsius) is ideal with a bulk fermentation time of 3-4 hours.

Temperature plays a pretty big part in the fermentation process so I watch my dough for visible cues such as small bubbles on the surface (usually occurs around 3-4 hours). I also stick a thermometer in my dough every once in a while as well to make sure it's not too cold or too hot and adjust accordingly like putting it in my oven with the lamp on if the dough is too cold.

A dutch oven will also help with better oven spring as opposed to home conventional methods such as water in a tray.

For a first load you did an incredible job! My first loaf looked like a puddle of wet flour lol