How do they know I'm doing the work related activities for 35hrs?

Is there any way you can even accurately keep track of exactly what you are doing? I've been sat here looking at jobs for an hour and I'm not sure how to convey that to them when I haven't been able to apply to basically anything and only one job was within my very limited ability and experience. How much evidence is sufficient to prove I've kept to my 35hrs? In what ways can I provide this evidence? Seriously, how do they know I'm keeping to my commitments? I can't understand it at all