Your accent is who you are, no need to apologize or even mention it. It sounds great and authentic.

Basically,you're creating an audio book, stating the obvious here. The more relaxed you are when reading, the relaxation will come through in your voice. I'm a world of AI generated voices reading books now, a real human is a luxury.

Any decent external mic will help the quality tremendously. Smartphone mics are a mess for quality. Something like this works great to start (see link)

Keep doing it. You'll improve at all of it the more you do it. Stick with books that interest you emotionally. The emotion and interest will be genuine and come through the recording.

Great first try.