You will have to go to the job centre in person to sign on each week. Signing on is a process where you sign to say that you have been actively looking for work but not found any. You will need be there in person to prove that you have not gone away on holiday or something like that. You may also be required to attend interviews to discuss what you are doing to look for work and possibly to be given any opportunities to apply for. The form filling can be done online though.