What do I need for a Landlord insurance?

[My Doan]

I been living at my house for 4 years and recently move out and want to turn it into a rental income, when I call my insurance company they force me switch my main home policy to them for them to sell me the insurance if not they will cancel my existing one. I call around and found state farm who would be able to give me a policy but it need a contract and tenant living in there. 1 I don’t a tenant. 2 I’m now paying more for landlord policy then my before policy when I live there? What am I doing wrong.? For the future property I acquire what should I do when it come to insurance policy?