You can often order a broadband package online. To do that, you need to go to the chosen provider’s website and choose your package.
You will then give your postcode to check if that package is available to you. Once the package is available in your area, you will be able to create a new account and pay for the new package.
Lastly, you may choose your delivery date. If you ask for installation, you will be able to schedule that as well. If everything goes well, within days you will be able to connect to the internet.