Can you post an image of what the house will look like?

Character and charm into the home...so you are looking for interior design ideas?

Is this a production build where paint colors, flooring, trim, etc come with the build or do you still have time to discuss the limited options? Tell us more.

It is too late to incorporate things like natural lighting and ventilation, but, sure, mix the two design concepts.

You want warm earthy colors, sunlight, so keep window treatments to a minimum and if you need some do linen panels.

Maybe a wool rug and art focusing on nature, the outdoors.

Minted

You have to decide what homey means for you.

For me it's rooms with cased doorways so each room could be painted a different color and I mean actual color. I used a natural pallet of blues, creams, greens, and no white other than the casing and ceiling. I also have lots of wood for a warm feeling.

My generic advice for making it homey would be no gray inside, no white counter tops or all white kitchen, and no ship-lath. None of those feel personal to me.

Native landscaping with elevation changes using berms. Improves your outdoor experience.

"Should I hire someone?"

A local architect that has designed houses in the past that you presently like.

If you're serious, post photos.

Landscape architect

Biophilic, mid-century modern and charm are not words I would expect to be used together. You’ve got your work cut out for you. Interview design professionals carefully and look at their work.

The work of Greene & Greene is the closest I can think of although its California Craftsman from an earlier age but well worth studying.

For the exterior xeriscape, ornamental grasses of various heights, fragrant groundcover in a rock garden like creeping thyme and chamomile. Succulents spilling out of large colorful pots. Bouganvilla vines, flowering hardy perennials like Sage. Rosemary and Lavender.

Interiors as suggested by @elcieg