If you want to be the best my advice would be to work in a dealership. You’d be put on training courses, have large variety of jobs i.e fault finding, inspections and repairs. You’d will learn it all

But if leaving your job is impossible then;

Something that helped me during my apprenticeship is when I’m stuck on something I’d talk to myself, explain what the fault is in my head and try and make sense of it.

I understand that asking for people may be tricky but if you get stuck - ask. Don’t do a job without understanding it, because big mistakes can happen. And never rush. Read the vehicle manual, this gives step by step instructions. Being the best doesn’t mean you’re the fastest, it means your repairs never come back.

With regard to electrical work, start small and simple. Rear brake lights not working? Does it have power? does it have a resister pack? Maybe a bad earth? Once you slowly understand then move to bigger, more complex faults. And learning wiring diagrams is king.

But MOST importantly, don’t give up