What is your goal? Do you want privacy, room darkening, sheers?

My goal is turning the space comfortable, bright and beautiful
Privacy is not necessarily! Thanks

If privacy is not an issue, consider no window coverings to allow the most light to enter. Otherwise pleated white linen sheers with top and bottom rod.

These frames and doors would look nice painted a bright pretty color like French Blue.

Hi! Tracey, could you please send me a picture! Thanks

Don't know what style nor colour scheme you're going for but here with soft fold roman shades on the windows.

These are secure at the bottom and top. Besides the tieback shown, these also slide back and forth on thin rods to open them. See the 1 inch hem. These ones do not look very sheer. Sheers let some view through.

Without the need for privacy or light filtering, maybe decide based on the room’s decor. If handy or hire a seamstress, purchase fabric and velcro for an easy and inexpensive solution.

From etsy.com. Lovely, and you can choose a color for the tape from a variety of colors.

https://www.etsy.com/listing/1734242082/exclusive-accent-roman-shade-window?epik=dj0yJnU9dXBxOHNaZGVNSE1qeTRFenYwaGxsV05tU2hmVnNQUU4mcD0wJm49TXR5UTBkY014TC1MWTkzek4wbExjdyZ0PUFBQUFBR2RPSTdF

It’s hard to say for sure not knowing your decor style, budget, if you’re renting or buying/own, etc.

My suggestions are just general ones for the style of windows. I think I see mountain or hill views and with that, as well as you wanting light and bright, I’d not cover those views in daylight. But I would want something I had the option of closing at night.

Two of your windows remind me of many I’ve seen in Europe that have indoor folding shutters to close at night. Examples … and again, I’m not suggesting these decor schemes, just showing shutters when opened:

Showing partly closed:

Once you have your furniture and decor in, you could add fabrics to the outside of the window nook for looks and texture, if you’d like —

This one has a curved rod:

For this one:

I’d use cafe curtains hung halfway to a bit higher than halfway. You could get sheers or something gauzy … or patterned. I don’t know your style to be more specific.

Example of rod height:

This is pretty:

Or, leave bare as they did in this kitchen:

Curious as to your location in the world, the views look amazing and the windows are very charming. :)

Not that it matters, but there is something about the photos that seems like it is not in teh US.

I guess that most are suggesting roman shades and that seems appropriate.

Thanks everyone for the advices. Yes, those are weird doors! I am in Portugal! I really don’t like shades! Thanks

how about this one? clean look

You say you don't like shades but what about a fabric roman shades? 't you like those either? with the width on each side the the windows and doors you don't have that many options. If you had more space you'd be able to hang a drapery on each side but you don't have that extra space. In my opinion a nice roman shade would look much better than what is presently hanging on your windows.