How do I prep this soil for planting?

Apologies if this is the wrong sub for this question. I have very limited experience with in-ground plants, but I just moved into a new place that has lots of open ground to work with. Granted, this patch is under two fairly large redwoods, so dominant shade and their root systems will have to be considered..

But my main question is what to do to prep this type of soil. I think there’s some clay in here, but I’m not sure.

Any ideas or recommendations based on these photos would be appreciated. Thank you!