You can buy your own home once you turn 18 and can legally sign a contract.
But you should make sure you're financially ready to pay for the house. If you want to buy a house make sure you have a stable enough job that you've been at for a few years at least.
Most banks won't give you a mortgage on a home unless you've been at your job for at least 1 or more years.
Next you need to have enough yearly income to cover the mortgage payments which is another thing the banks will look at when giving you a mortgage.
Also only buy what you can afford. Even though you might qualify for a larger home mortgage on a more expensive house you should buy less than you can afford so you won't be what they call house poor.
You'll also need a down payment which could be at least $10,000.00 to $20,000.00 or more depending on the mortgage amount.