Can a landlord charge $2.500.00 first month and $2,500 2nd month rent plus $2,500 security or $7,500 for move in unfurnished home in Ca?

Yes, that is what would be owing on the day you move in.

It is referred to, first and last month's rent plus the security deposit, regardless

of the amount of rent. The apartment would be rented as you see it, whether it

is furnished or unfurnished.

Basically, a landlord can charge any price they want to. You don't have to rent it if you don't like the price.

A landlord can't change the price once a lease contract has been agreed upon until it is time to renew the lease.

Yes if that is what the going rate is for that property, it is a simple offer and acceptance contract, the landlord offers, the potential tenant accepts and a contract is signed, or the potential tenant rejects and doesn't sign and looks elsewhere

Yes

yes.

He can charge you first month's rent, last month's rent, and security deposit.

Yes.

Absolutely yes.legally

Yes it is legal. If you cannot afford it then you cannot afford the rent.