Looking for a apprtment for couple

I am a Chinese student from audencia. My boyfriend is French and he works in Nantes. We hope to find an apartment for couples. The minimum residence time is one year. Starting from September 2019, we hope to be an independent apartment. We want the contract to fill in our names and have separate bedrooms and living rooms, washrooms. The rent is between 500 and 680 euros. Thank you.