Oh shit I think I remember I've read stuffs similar with your description but I don't remember the title wait I'll try my best to find it
Oh I found it "Otherworldly Sword King's Survival Records"
https://www.mangago.zone/read-manga/otherworldly_sword_king_s_survival_records/
Not sure of I'm right or not but that's the only manga that popped in my mind
Oh I just checked it's slightly different from your description aw :(
It’s okay, thank you for trying ^^
Just remembered a story I read a long long time ago so my memory is a bit hazy but it starts off with a female humanoid dragon in a cave on the mountains and she gets woken up by some guy that wants to kill her for some reason and they fight??? After that they both acknowledged each other's strength and became friends or something.
If I remember correctly, the female dragon had white hair if that helps.