Jose Lopez

Question, I was unemployed all of 2023/2024 (no earnings income). And rented a room in my flat for circa £9,300 Is the difference (9,300-7,500 = 1,800) liable for tax? if so at what rate (I read tax is liable at one's marginal rate, but mine is zero as I did not earn monies above the personal allowance threshold). Finally do I need to file a Self-Assessment? Many thanks