Have you tried doing some searches for window coverings? https://www.houzz.com/photos/bay-window-curtains-phbr0lbl-bl~l_6461

Emily's suggestion is a great start. Also what is your preference / style ? Looks like privacy might be an issue, do yo need shading from the sun ?

I like bay windows where the entire opening is treated as one large window with drapery panels on either side. I might allow the panels to be wide enough to cover most of the window if pulled closed, but I would buy a long enough hanging rod to position drapes to either side of outer windows (allowing window to feel larger). Your picture does not show distance from window to ceiling, but I usually like hanging the rod just under the crown molding to make ceilings feel taller.

A few more photos of your space would help people understand your space.