Do recording studios and labels provide instruments?

First things first, Record Labels aren't what they used to be anymore. A lot of independent labels are rising.

I suggest to go independent and not rely on a record deal from a major company. You should first find a team that will be with you and help you. And find a studio in your area to start recording.

Team is important in this case.

First off your not going to get signed by a label by providing a demo, Or at least not one that's big enough to provide instruments in most cases, But that's not to say you cant contact them and ask if they do provide instruments and then pay for the recording services, Big recording company's don't gamble on providing free services in hopes of selling a few albums, You need to be established and show them you can sell an album before they sign you these days, In which case they take a nice slice of the pie, Take my word for it kid there's people posting YouTube videos with a whole lot more than 56 views not getting signed to record labels,

No , usually not, I have used studios in the past you hire the musicians that are used for the finished product.You pay for it. not the label or studio.they will provide the musicians,I, know i have done studio work for many wannabes , Most studio,s do have access to keys or a piano if needed, And sending in a demo means nothing.

Do you mean backing musicians? They are hired through the studio. Do you mean is there a piano in the studio? That's also yes. But you need to contact the studio(s) in question and discuss the details with them.

Ask them when you send your demo.