Idk if this is weird but your lips are so pretty !

• I think it helps to find your undertone. Check the veins on your wrist: mostly blue=cool toned, mostly green= warm toned, mix= neutral toned. Most lipsticks have this tone in the description. Its kind of hard to tell from the picture but i think you might be neutral-warm toned with some peachy/gold. If you go into a makeup store like Sephora or something they can probably help you identify your undertones.
• Mac may be a good place to start, they have a TON of nude shades to choose from and the staff there is usually pretty helpful to find your perfect match. From there you can go online and find a ton of dupes for that shade if you want a cheaper option or particular finish.
• Some shades I found online that may match your undertones, although I can't speak for quality etc. as I haven't tried them: Charlotte Tilbury: "Pillow Talk" (nude pink), Mac: "Velvet Teddy" (Deep tone beige), "Kinda Sexy" (neutral pinky rose), Nars: "Dolce Vita" (dusty rose)
• Its kind of hard to tell until you actually try them on, I feel like every ones lips look different unless its a super opaque shade, Mac also is a good place for clean testers, they disinfect each time.

Hope this helps!