Hi Miguel,
For most qualifications, the modules only start in October and February. As it is too late to register for the February start, the next available start date is October 2023.
Each module will have a defined start and end date, with assignments that you will need to submit to deadlines. You can find out more about how distance learning with the Open university works here:
https://www.open.ac.uk/courses/what-is-distance-learning
Registrations for the October start are currently closed, but due to be open from mid-March, and will remain open until the first week of September
In the meantime, you may want to check out some useful resources, on the Jumpstart University section of our OpenLearn website, to prepare for university level study:
https://www.open.edu/openlearn/education-development/jumpstart-university/