You have found a program you want to apply for and try to understand how to apply. This is different for each program, but most application processes have common procedures.
First of all, you must know all applications are done through the institution that offers the program. You cannot apply through this website. On each program page you will find a link 'Go to the program's webpage' which will bring you to the website of the institution where you can apply. If you cannot find out where on the website of the organizing institution you can apply for a program, contact them.
Make sure you meet the entry requirements. These can be found on the program page. Although many undergraduate programs seem to have to entry requirements, most universities only accept students aged 18 years and older. Contact the organizing institution to find out if this is the case.
Some documents you can expect to prepare for the application are:
Usually, when you apply you do not immediately pay the full fee for the program. You application will first be reviewed, after which you will receive information on how to pay the fees. Some institutions charge an application fee. This is a fee you do have to pay when you apply and is almost always non-refundable.