Here's a shed I recently finished building. One of those pre-manufactured jobbies you put together yourself, and I literally did just that.
Nice work. I have a 9m^2 shed in boxes in the garage awaiting construction. But some idiot didn't manage to get bags of cement before lockdown, so it will have to wait.
I'm just using some battery powered LED lights I bought at M10 called a Blazing LED Jumbo Light Switch.
I have them in the boat on the underside of seats with storage underneath. I bought 4 as they were cheap and I thought they would have reduced life expectancy in marine application. They've surprised me by lasting a few years, so I'm going to use the spares in the new shed.
I'm sure they would be OK in garden shed.
Edited: to correct product name