Trying to find a first job with no experience or connections?

I’m 19, been searching for work for the past year consistently and few years on and off. Being at home all day is horrible for my mental health and so I’m really desperate to find work. Only issue is, as I’ve been told by everyone around me, it’s about who you know, not what you know.

This is all well and good, but I know nobody. I have absolutely no friends, my family are very to themselves too. I had a trial shift at a kitchen and it went amazing, but I didn’t get the job since the HR manager’s niece was hired instead. I’ve had a mcdonald’s interview last week, got rejected since i turned up too early (15 minutes!!! Punctuality man!!!) Had a Costa interview yesterday, got rejected this morning since they found someone with experience who they wouldn’t have to train. Have a Tesco interview on saturday and I’m just dreading it now I see no point in it.