Regarding accommodation, since we opted for private accommodation, if the visa officer asks me about the address, should I share the address of my relatives with them in UK?

No, you should provide the address of your actual private accommodation, not your relatives’ address, unless you plan to stay with them.

The UK Home Office requires the address where you will be staying to confirm you have suitable accommodation for your arrival. If your private accommodation is not confirmed yet, you can state "private accommodation" in your application and update the Home Office once you have the exact address.

If you need help updating your accommodation details, contact your LeapScholar counsellor.